How Did I Know The Rock Had Become Live?
August 8, 2009
All marine aquarists are aware of live rock. It’s the stuff that perhaps the majority use for bio- filtration and it’s also excellent as décor, be it a reef or a fish only system.
Good mature live rock has the usual bacteria present, those that convert the toxins ammonia and nitrite to the much safer nitrate. Unlike a canister filter where the nitrogen cycle stops after the production of nitrate, live rock within reason will deal with nitrate. This is because the bacteria that dwell deep inside the rock would also prefer to use oxygen directly, but because it is in very short supply they remove oxygen from nitrate which breaks it down.
When I set up my current soft coral reef system I used two canister filters for the bio-filtration. (The photo shows the reef in part. You can tell I took the photo!) The bio- media was Eheim sintered glass. It worked very well. Being aware that nitrate could become excessive I built a denitrator based on suphur and this ran from when nitrate was noted as being present even though the reading was very low. Better to defeat a potential problem than wait to tackle a real one. Once the denitrator was matured the nitrate disappeared and I never had any readings at all. This was over the first 5½ years of the aquarium’s life. It has to be said that the fish load is very low; there are two small fish (a blue damsel and a flame angel) in 43 gallons net of seawater.
The reef is built of what is named ‘grotto rock’. This doesn’t come from any grotto so why the name I don’t know, however it’s ideal for marine use as it is totally inert and full of crevices and holes. Just as important, it’s very porous. The rock comes in all sorts of shapes and sizes and it was great fun creating the reef.
The reef developed over the years and I noted the lack of nitrates. I thought I’d do a little experiment at one point to prove the effectiveness of the denitrator; this experiment consisted of turning if off. Difficult!
I monitored the nitrate level and found that all readings were zero (I suppose I ought to state that nitrate was undetectable with the test kit). I left the denitrator off for a week, two weeks, which turned into months. Still nitrate didn’t appear. The canister filters continued to run so nitrate would be produced.
I like looking at the reef from various points in addition to the front and sides. This often involves lying on the floor and peering into the aquarium. This sometimes occurs at night when most of the little beasties are about. The rocks I thought looked more like live rock than the real stuff, with all the worm growths, algae etc. I then wondered if it was in fact live. This thought was supported by the lack of nitrate, the canisters were producing it and perhaps bacteria were removing it? I realized that I did routine seawater changes and this would tend to reduce nitrate levels as well.
The rocks were now live, why not? It was an excellent home for bacteria after all. However, at the end of the day a rock looks like a rock, there’s no way a bacteria presence can be checked. It is a known fact that bacteria exist on surfaces within the aquarium in addition to any intended bio-filtration area, but would there be sufficient to support the aquarium completely? Surely the canister filters would be taking the majority of the bio-load?
I have two canister filters running as said, so it was easy to check. At the next scheduled clean of one of the canisters I removed the bio-media and ran the canister empty (seawater is returned to the surface for oxygenation and to agitate the surface). A careful watch was kept and there weren’t any unwanted effects.
So far so good, but the next stage was a little more cautious. Even though the bio-media from the first canister had gone, maybe the second canister was handling everything, so with the second canister, when the time was chosen to remove some bio-filtration media I only removed half of that present. Hopefully that left would prevent any major disaster from occurring. The amount left was one quarter of the total original amount. This was left for a month with everything being carefully watched. No problems.
Now came the crunch – remove the final bio-media. This was done and both canisters now ran empty. Feeding and maintenance continued as though nothing had changed. Nothing untoward happened.
The system continues to run normally and it is now approaching its 7th year. The inert rock is now live.
To be honest I wasn’t really surprised, though it was very sound to use caution. One way of producing live rock is to mix inert rock in with live; the higher the live proportion the quicker the inert variety converts (it still takes quite some time). There wasn’t any live rock in the system at all at the start; it was all inert, so how did it convert?
The first possibility is that ‘overspill’ from the canisters occurred though perhaps this is unlikely, I don’t know. The second is that bacteria developed on and in the rocks naturally and these expanded in number.
To my mind the most likely explanation is that the bacteria were introduced, though some could have appeared naturally as suggested above. Most of the corals that were introduced are attached to rocks and of course they were attached to these when collected – these rocks are live. So the inert rocks were colonized by the bacteria from the live coral rocks.
When the bio-media was slowly removed from the canisters the bacteria on and in the rocks would have expanded to deal with the increased load and, hey presto, the system is now based on live rock.
The denitrator sulphur media has been cleaned and is not in use. I haven’t actually removed the unit as it isn’t in the way. The good thing is there isn’t any more need for it to be maintained though the maintenance wasn’t a problem. The worst part was the flow, denitrators have a very slow flow and this was occasionally problematical and a bit of a headache. No more of that though.
A Worrying Failure
June 23, 2009
Marine aquarists make use of varying types of equipment on their fish only or reef aquariums. This equipment is generally reliable nowadays but nevertheless any device has the potential to fail.
There are many canister filters in use for either mechanical or bio-filtration. Though live rock is the bio-filtration of choice for the modern aquarium, canisters are still in use by many for this essential task. There isn’t any reason why they shouldn’t be, though there are drawbacks.
Live rock is able, within reason, to deal with nitrate. In other words live rock should perform the full nitrogen cycle. This is the major drawback with canister filters, nitrate is the end product. This is because the bio-media within the canister is oxygen rich and there isn’t any need for oxygen to be obtained elsewhere. Nitrate reducing bacteria require an environment very low in oxygen which forces them to seek an oxygen supply elsewhere; nitrate is present so oxygen is taken from that which breaks the nitrate down. It follows that an aquarist using a canister filter needs to keep a closer eye on nitrate levels and carry out the requisite correctly sized seawater changes.
Another advantage of live rock is that there isn’t anything to break down, as opposed to a canister filter where there is an electric pump. As already said modern canisters are reliable though recommended models should be sought when purchasing, but what if a breakdown does occur?
Failure of the electric motor means that the whole function of the canister ceases as seawater flow stops completely. When an aquarist does routine maintenance the output from various devices is checked, an operation that takes hardly any time. However, it is more likely than not that a failure will occur at an inconvenient moment. Canister electrics are usually very quiet nowadays and there isn’t any indication of trouble apart from seawater output ceasing. So the first thing is to note the output anytime possible, such as at feeding time and when starting to simply observe and admire the aquarium. It only takes seconds.
A stopped canister filter should be switched off and then on again a couple of times, this sometimes frees up the motor. Don’t count on it though! If the motor does re-start then as soon as possible check the shaft and impellor for debris. However, before attempting to re-start by switching off and on note the comments in the following paragraphs.
Once the output from the canister is noted to have stopped there isn’t any way of knowing when it stopped. This is a worry because involved is the life support for the system, the bacteria. How are they faring?
It could be that the fish have been acting strangely and that is how the lack of seawater output was noticed. If this is the case then the failure occurred quite some time ago as there has been time for toxics to build up in the seawater. The first action is a seawater change, the size of which depends on the severity of the situation. If the fish are really obviously in trouble then 25% is not excessive, more if necessary, and the change should be done as soon as possible. The aquarist should be prepared to carry out a further change if necessary.
The aquarist should ensure that other equipment, namely the protein skimmer and seawater circulators, are working at maximum efficiency to ensure maximum oxygen intake and minimum bio loading (the skimmer should remove substances reducing the load on the bio-filter).
A regime of seawater testing should be introduced. Once the situation is under control the tests can be done once daily, but it is often better and more reassuring for the aquarist to do tests morning and evening. The tests are of course ammonia and nitrite. The only ongoing acceptable test result is ‘nil’ or perhaps more accurately ‘undetectable’.
If it is found that the canister filter electric motor has failed but the fish are not showing symptoms of distress then the failure is probably quite recent. Again, test the seawater and do a change if necessary.
In both cases, fish distressed or not, cease feeding until an effective bio-filter is back in operation.
The speed that toxics develop in the seawater depends to a large extent on the fish numbers present. Corals present a far lower bio-load.
As soon as possible deal with the canister filter. At this point it is known that switching it on and off didn’t work! Ensure it is switched off and disconnect from the tubing. Check the impellor and shaft, there could have been a failure, if jammed the problem can usually be sorted out. If there is a breakage spares are usually available, obtain them by the fastest possible means even if it incurs extra cost. (Obtain the spares from the local fish shop if possible to avoid any delay.) Check that the input and output tubing is not blocked, this could occur over time.
If the electric motor itself has failed then a new canister filter should be obtained (or better two, see below). When the replacement device is available bio-media can be transferred and if required extra added. Until the new device arrives the bio-media already held should be kept within the aquarium seawater preferably in a high flow area so that at least some of the bacteria are retained. When the new canister is running there is a clear need for monitoring the seawater condition, as it will be similar to though not as extensive as maturing again. Seawater quality can be maintained by additional seawater changes, new seawater should be available at all times until the aquarist is sure all is well.
If the canister has been off for a long time do not re-start it and allow it to continue running. Disconnect and drain the internal seawater out completely. Refill and then start and run. This is because there is a danger that the seawater within the canister could be heavily contaminated. If the canister is likely to have been off for only a short period, just re-start. It is worthwhile carrying out daily seawater tests for a week in either case to ensure the bio-filter is effective. After re-start, feeding should be with considerable caution as the bio-filtration may well be weakened and need to re-build. Again, ensure that the protein skimmer and seawater circulation pumps are at maximum efficiency.
To largely avoid a problem such as described, unlikely as it usually is, when the system is designed it is a good idea to employ two canister filters. This will of course mean a little more cost, but the filters can be smaller. Instead of obtaining one which can handle the net gallonage of the system, obtain two. These together in total should handle the net gallonage, but it is a good idea to have both of them a little oversized. They can be routinely serviced alternatively so there isn’t any extra work generated. If the need for canister bio-filtration is removed in the future they are useful for mechanical or other types of filtration.
It is generally unlikely that a modern canister filter will fail, particularly if it is adequately routinely serviced. If it does fail the shaft/impellor could be affected by accumulated debris and/or calcareous buildup, or tube blockages could be present. Observation is the main preventative.
The Long One
June 7, 2009
Like the majority of aquarists I have a schedule for maintaining my aquarium. With the commitments I have and the time available I’ve found that this schedule saves time – usually.
Saving time doesn’t always occur, sometimes, and it is infrequent, something occurs which takes up a lot more time. Not today though, all went well mainly.
My schedule depends on a number. Number one is clean the glass. Wow, that’s it! Number two is the same as one plus the intake filters on some powerheads, plus a routine seawater change. Number three is the same as one. Number four is a comprehensive clean. Included with all of these numbers is a check for any unwanted organisms such as Aiptasia. So as can be seen maintenance covers a four week cycle.
Maintenance is nearly always done on a Sunday as there is time available, in the morning anyway. It all sounds a bit military maybe, but it works.
The number for today is four, the long one. New seawater ready and waiting, cleaning equipment near the aquarium. The aquarium is surrounded by carpet, so polythene covers are in place. They catch the drips and minor splashes very well.
The very first thing is to clean, with a hard toothbrush, my miniscule algae scrubber. This developed by itself and is obviously doing something as it exists! There must be some level of nutrients in the seawater feeding it. The photo shows it – I did say it is tiny, about 3 inches across and 2 inches deep! The seawater flow is from the hang-on skimmer.
Next the bracing struts and viewing glasses are cleaned with an algae magnet. Only the front and one end viewing glass are done, encrusting algae is permitted to grow on the others.
Exciting stuff this isn’t it! Now the four powerheads which sit in a small compartment are checked. The powerheads driving the under-reef spray bar and anti-phosphate filter have sponge intake filters and these need thorough attention. The anti-phosphate filter is shown in the photo; it is a homemade hang-on type. (Taking the photo was difficult, it is under an open stairway and space is restricted.) The other is an anti-nitrate filter, again homemade but this isn’t in use.
This maintenance is progressing well. The Eheim canister filter is next, the mechanical media has to be checked. This is comprised of fine and medium sponges and it can be surprising how much they catch from what appears to be clean seawater. I have to save numerous very small shrimps as well; these are placed in the display aquarium ensuring the fish don’t get them. There are numbers on the filters – this is from when they were both used for biological purposes so that they could be selected for cleaning, this doesn’t apply now as the biological media has been removed.
Getting there now and it is usually at this point that a cup of coffee appears. Thanks!
Siphoning is next on the agenda but before the main siphon tube is used, I attack any unwanted organisms. Today I located a few Aiptasia and these were dealt with. I’ll have to deal with more as time passes; they are never eliminated, probably because there are so many nooks and crannies in a reef aquarium. As long as they are not left to their own devices for too long they aren’t a problem.
So out come gallons of seawater with the siphon tube, this seawater will be dumped. (I used to use it for brine shrimp production but no longer do so.) At this time any debris spotted on the base of the aquarium is removed. There isn’t much base to be seen but it is checked anyway.
The new seawater is placed on the stairs above the aquarium and my wife kindly makes sure the tube doesn’t come out (not the siphon tube, one that is considerably longer). In goes the seawater.
Not quite done. I manually add certain additives to the seawater, these being calcium, bicarbonate and carbonate powder (for alkalinity) and iodine. Calcium is maintained at around 420ppm and alkalinity at around 4.0meq/L. I don’t measure the iodine level as it is only added once every two weeks at the minimum dose, there has never been a problem.
Nearly time to pack up now, just give the glass bracing struts a clean with a paper towel, likewise the viewing glasses. A check with the hydrometer is required, this is fine at 1024.
Final job – give the fluorescent tubes a wipe. Now it’s all done.
No, not quite. The two fish get some brine shrimp for being so patient!
The Move to Natural Methods
April 12, 2009
Many modern marine aquariums use ‘natural’ methods as much as possible. This has been achieved by the advances in knowledge that have been made over the last few years.
Some aquarists argue that it is impossible to keep an aquarium without using natural methods and I can see where they are coming from. The point they have in mind is bio-filtration, all those hard working bacteria getting rid of the toxins in the seawater. Without them we’d be in a sorry state. It’s true as well that this filtration is natural. However, if the bacteria colonies are housed in a canister filter then it isn’t completely natural, the home for the bacteria is being provided by our technology. Nothing wrong with that as it stands.
A fully natural method for bio-filtration, staying with the example, is live rock. This rock mainly comes from the wild and has bacteria present. It is a really good filtration media and, unlike the canister filter, within reason the bacteria can deal with nitrate as well. Can’t be bad!
There are new commodities on the market that are designed to replace live rock. This is a rock that appears very similar to the fully natural variety but needs the bacteria colonies kick starting in the same way a canister filter does. One running the new rocks are suitable homes for all bacteria including those that deal with nitrate. This isn’t removing ‘natural’ filtration; the difference is purely the type of rock. There isn’t any electric motor required. It also reduces the demand from the wild, unless the live rock is aquacultured in the wild.
Anyway, getting back on track, there are a few ways that an aquarist could use natural methods. Think of filtration by algae, deep sand beds, plenums, mangroves etc.
The link below is to a website article where natural methods are definitely in mind.
http://www.practicalfishkeeping.co.uk/pfk/pages/show_article.php?article_id=551
Bio-Media Removed
March 4, 2009
When I first started my current reef aquarium over six years ago I didn’t use any live rock. Instead, for the bio-filtration I used canister filters.
There are two Eheim Ecco canister filters installed and I have to say that they are good, well constructed and to date absolutely reliable. Anyway that’s not what I’m on about here.
Over the six years many corals on rocks have been introduced and the rock that was inert and dead is now live. It hasn’t the potential diversity of life that natural live rock has, but it has a lot of organisms on it and probably in it – there are tiny tube worms by the hundred and a high population of tiny creatures that appear mostly at night. It is also typical live rock in appearance as far as encrusting algae and the like are concerned. I have to say I can’t see that much rock anyway as most is covered up by some organism or another.
I suspected that the rock was live because of nitrate. As I had elected to use canister filters a home made denitrator had been fitted as well. There has only ever been the tiniest presence of nitrate according to the tests and it was so faint my wife and I were unsure about that. Eventually this trace disappeared as well and never re-appeared. So about two years after the trace, if there was one, had disappeared I turned the denitrator off. There continued to be no trace whatsoever of nitrate and the denitrator has remained off.
If there was nitrate present and it had disappeared then routine seawater changes wouldn’t have been the cause as these have been done bi-weekly ever since the aquarium started (though at first they were weekly). It wasn’t the denitrator as this was turned off and nothing re-appeared. I assumed that bacteria had colonized the very porous reef rocks and these were dealing with any nitrate, as well as ammonia and nitrite. I decided to remove the bio media from one of the canisters. It didn’t happen.
The canisters, both of them, were left running in full bio-mode as I didn’t do anything because of the reef, it was so successful and natural looking that I was afraid that if I made a mistake the livestock would suffer and I wouldn’t have time to generate a new bacteria population. After a while, I thought that this was ridiculous – and it was as there are two canisters and they both have the capacity to bio-filter the aquarium. So I removed the media from one, then started it up again empty as it is used for surface agitation.
To date, six months down the line, there hasn’t been a problem. So now I’m thinking I’ll remove the bio-media from the other canister. Going on previous performance it’ll be a while before anything is done! I feel certain that there isn’t a need for bio-filtration with the canisters any more.
When I removed the bio-media I expected that there would be visible life within it (Eheim sintered glass). There wasn’t, none at all, at least any I noticed. The aquarium is full of life, mobile and otherwise, so this was a surprise. On cleaning mechanical media I am always rescuing tiny shrimps.
I was really pleased with the state of the bio-media. When washed only a very small dusting of dirt appeared, one rinse and it was gone. This was down to the four weekly mechanical media cleaning, also the mechanical media set-up. The entire mechanical media was before the bio-media, taking the form of a coarse sponge, a very fine filter ‘cloth’ one half inch thick and another fine sponge, so the filter ‘cloth’ was sandwiched tightly between the sponges. It clearly worked.
During the operation on the canister I noticed a fair growth of some toadstools in one area on the reef. All the corals grow at a quite fast rate and the toadstools are the fastest. So out came the sharp scissors and off came their heads. Very drastic sounding but it has been done several times before without mishap. They grow back rapidly.
I also noticed more new corals growing beneath, toadstools again, six in all. Four were removed entirely and two left. The photo (sorry, it isn’t particularly good) shows the cut ‘stalks’ and also the two small new ones that were left.
The cut corals look awful at first but they don’t stay that way for long. First polyps re-grow, then the heads start to increase horizontally and the stalks lengthen.
It’s all quite miraculous really.
Live Rock A ‘Different’ Way
March 1, 2009
Live rock is quite rightly highly rated by marine aquarists, particularly by those with a reef, for both its filtration capabilities and its appearance. It is natural, what could be better than that? Well, nothing really, but nevertheless there are drawbacks in its use.
The first negative is that it is expensive and it’s bound to be with the cost of air freight never mind transport to the final destination in the US or Europe. This cost is generated by both weight and bulk. Nevertheless, aquarists buy it and can reduce their costs by using base rock underneath the reef which is less expensive. Another way is to reduce the amount required by putting face rock on a framework of plastic supports which means less is required, though care has to be taken that there is still an adequate amount for effective bio-filtration.
Some enterprising aquarists manufacture their own live rock though the numbers who do this are low and the result is not usually as good looking as the real stuff (in my opinion).
Other aquarists use dead inert rock as a reef and employ canister filters for the bio-filtration. This is what I did with my current reef. The bio-media is being removed from the canisters as the rocks are now live.
The last paragraph leads me into the reason for this text. My aquarium (over six years old) is now using rocks as its main bio-filtration, as said the rocks were previously ‘dead’. After setting up the aquarium, before the canisters could be used they had to be ‘matured’, that is a bacterial culture had to be started within them. It could have been done another way – I could probably have used maturation fluid to establish a bacteria colony on the rocks in the first place, they are very porous. The rocks when used initially were not very ‘reefy’ looking though they are now.
If only there were rocks that were both porous and ‘reefy’ in appearance many aquarists would be pleased. Well, it seems there are now.
Artificial ceramic reef ‘rocks’ were brought to my attention by a comment on the forum, they are named Vida Rocks. So of course, never having heard of them, I went onto the internet and had a look. I have to say that the appearance of the rocks seems good, they are natural looking taking the shape of ordinary rocks, arches etc. An aquarist would be able to create a good looking aquascape with them.
The rocks are stated to be highly porous. This means that they should present a suitable habitat for those bacteria that protect our livestock. The bacteria culture would have to be kick started in the same way that a canister filter is by the use of maturation fluid, but this is not a problem. With this method nitrate will probably appear in the aquarium but this is easily reduced by a seawater change. As the ceramic article is porous the possibility, or maybe probability, arises that nitrate could be dealt with as with natural live rock. Bacteria could establish inside the rock in low oxygen areas. It would be great if this occurred.
So we have a system that will present an ‘authentic’ reef appearance and provide adequate bio-filtration. Over time the rocks will become more natural looking as organisms take over the surface areas. These organisms could be introduced on rocks with corals attached.
There must be disadvantages though, and there are. The ceramic rock is not loaded with bacteria by Mother Nature as the natural stuff is. Also, the life forms that could appear in the aquarium when using natural live rocks are not there. The life that could appear with natural rocks is a gift, and there is often quite a lot of it even after the transport time and ‘curing’ process. However, natural live rock could also bring undesirables such as aiptasia (glass anemones) etc which will obviously not occur with the ceramic type. Undesirables could appear in the course of time anyway as coral rocks will be introduced to a reef system and so the threat remains.
I am all for the move to ‘natural’ based aquarium husbandry as are most aquarists and this hasn’t changed. Live rock and deep sand beds (DSB’s) are a good example. This ceramic rock has aroused my interest. If the ceramic rock has been ‘matured’ with bacteria and is combined with a DSB it would amount to very nearly the same thing, with a difference.
The difference is that live rock for the most part is taken from the wild reef areas. By using the manufactured rock the demand on the wild resources would be reduced which generally would be good. Local fish shops (LFS’s) would probably state that it would affect their trade, so they could sell the ceramic variety. They could even sell more of it as it would no doubt be cheaper particularly as it does not have to be air freighted, at least in the US where it is manufactured (I do not know the price).
For an aquarist who is considering extending their reef (or fish only aquascape) this ceramic rock could be considered. It will need a little time to mature (bacteria) so if increased stocking is envisaged care would be needed.
For an aquarist who is just setting up a marine system it is a consideration as a particular aquascape design can more or less be achieved. The normal constraints on stocking after maturation would apply, as with a canister filter. Unlike a canister filter, hopefully the industrious bacteria within the ceramic rock would within reason have an effect on nitrate levels.
Have a look and see what you think:
I look forward to comments by aquarists who use it.
(Aquaristsonline.com does not have any links, personal or commercial, with the above internet site)
How Long Should You Leave Refugium Lights On For
February 28, 2009
Refugiums are becoming more and more popular nowadays as people are starting to realise the beneift that they can have upon the aquarium.
Refugiums, as the name states are a refuge for animals to live without fear of predation. It is also an area where macro algae can be grown to assist in the removal of nutrients from the water.
In a normal refugium macro algae is grown to assist in the removal of nitrate and phosphate. In the refugium may also be a scattering of sand, a deep sand bed or even a mud bed.
Macro algae normally will only remove nutrients when it is actively growing and for this to happen it requires a light source.
The best light source to use is lighting which is correct for the growth of plants – this is normally in the lower end of the kelvin scale.
In the display aquarium the lights are left on for between 8 and 12 hours however how long should the lights be left on above the refugium?
There are two answers to this question:
1. The lights are left on for a 24 hour period. With this method the algae is allowed to grow continuously and therefore remove more nutrients from the water column.
2. The lights are lit in what is termed reverse light cycle. What this means is that the lights above the refugium come on when the display aquarium lighting goes off and turn off when the display aquarium lighting comes on.
So what do I recommend and why?
Both options are valid options however I would recommend option 2.
The reason for this is that I like to follow nature. In nature the grass beds are not subject to lighting over a 24 hour period – the receive light when the sun is out!
I also believe that the algae needs a ‘rest’. It requires a lot of energy for the algae to grow and if it grows continuously then problems may occur. This is not something that has been scientifically proven but is something that I believe could happen. It also needs to be remembered that in the refugium other organisms also exist. There will be various types of organisms which, like most life would prefer a period of darkness. I read somewhere, unfortunately I cannot remember where, that in a refugium which was provided with darkness the population of organisms grew however if the lights were on continuously the population did not grow as fast.
There is another area which is important and both of the above methods provide this – pH stability. When the lights go out above the display aquarium there is normally a slight pH drop throughout the hours of darkness. If the refugium is lit throughout these hours of darkness then the pH drop may be countered. As with anything in this hobby stability is key and this is just another area where this stability can be maintained.
So in my opinion the refugium can be lit of a 24 hour period or it can be lit on a reverse cycle however if I was to choose then I would choose reverse cycle for the reasons listed above.
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