Caulerpa

Mention the word ‘algae’ to a marine aquarist and the aquarist’s face might turn white, before he or she spins round to look at their aquarium and ask, in a panicky voice, ‘Where?’

We are all aware of that concern: nuisance algae! The stuff that covers everything in long thin strands of green or covers with a thin sheet of dark red or black looking film. Nuisance algae can be combated or avoided in the first place. But this isn’t about nuisance algae.

This is about nice algae for the aquarium! In the marine world there are a lot of types of algae that could come under the word ‘nice.’ They are decorative and sort after. Aquarists who use live rock may have been fortunate to see some grow.

Of course there is one algae that is essential, and this is the single celled type called zooxanthellae, or symbiotic algae, which dwells in the flesh of corals.

The algae here is Caulerpa sp. This is green, though the shade of green can vary, and generally grows longish leaves (sometimes up to 12″) which have various ‘patterns.’ The algae spreads by putting out runners, from the top of which the leaves appear. Underneath are holdfasts, which look a little like roots. The roots are simply anchors, however, as the caulerpa feeds through the leaves. This macro algae is very useful to the marine aquarist for decorative and/or filtration purposes.

A great deal could be written but all that will be done is a general description of the main types and what they could be used for.

The first and probably best known is Caulerpa prolifera. The leaves are plain and have straight edges which taper to a point. The leaves are normally flat. Growth is fairly speedy.

Two more attractive types are Caulerpa mexicana and Caulerpa seratuloides. They both have leaves that look a little like bird feathers, with individual sections sprouting from the stalk sideways on both sides from bottom to tip. These types could show rapid growth.

A different appearance from the previous types is Caulerpa racemosa. It is often called grape caulerpa because of the appearance: the leaves are bunches of small grape-like growths attached to the stalks. This type is more slow growing and more difficult to cultivate successfully.

What can be done with caulerpa? For decorative purposes it would of course be in the display aquarium, where it can look very attractive. However, the aquarist must be sure it doesn’t outgrow its welcome as some can spread rapidly. I had some Caulerpa mexicana in a previous aquarium and it was certainly attractive, though I had to harvest it regularly to maintain control.

The other area that caulerpa is often found is in a sump. Aquarists grow it there so that it can act as a filter. As it is an algae, it uses the same nutrients that nuisance algae does, that is nitrate and phosphate. In doing so it robs any potential nuisance algae of food. Even if hobby test kits indicate zero (undetectable) for nitrate and phosphate, it could well be that there is a low presence. Planting a piece of caulerpa and watching to see if it grows is possibly an indicator. Obviously, algae in a display aquarium will also reduce nutrients.

As with all plants caulerpa needs light. Fluorescent tubes such as T5’s or metal halide bulbs should be fine, so growth in a display aquarium should not be a problem as far as this is concerned.

Caulerpa grown in a sump can be lit a little differently. A fluorescent light with reflector will suffice, the light is usually quite close to the seawater surface. There may be an advantage in using a tube that has a K (Kelvin) value that is lower than normal for a display aquarium, such as 6500K. Or a white marine type can be used, around 10000K. In addition there are two ways of timing the ‘light on’ period. First is to leave the light on all the time without any dark period, which doesn’t seem to have any detrimental effect on the caulerpa, and the second is to have the light on period when the display aquarium is in the light off period. The second option could assist with pH stability – pH could fall a little when the display is in the dark period, but with the caulerpa lit this is counteracted.

When planting in a display aquarium, try the type of choice and see if there is any success. If not, try another type. In the sump, it could be a good idea to plant more than one type and see which ’takes’ first.

Caulerpa should be harvested from time to time, always leaving plenty to continue growth. As the plant uses nutrients, removing the caulerpa in a controlled manner also exports nutrients.

The aquarist may find that the caulerpa in the display aquarium is disappearing. Have a look at algae loving fish such as surgeons and rabbit fish – they could be fat and very happy!

Important Note: Caulerpa in the aquarium is fine, decorative and useful. However, when harvesting, or simply removing caulerpa of any type it must not be thrown away into the sea. Caulerpa is invasive and can and is causing problems.

In some areas caulerpa is banned because of problems. Please check the position in your area before obtaining caulerpa.

For some information here is a link:

http://www.sccat.net/#the-caulerpa-information-center-1e86c5

---

Can Tonga Live Rock Provide Enough Filtration?

Live rock as has been said time and time again is a phenomenal filtration medium. There are various different types of live rock available all of which provide the required filtration to the aquarium if enough is placed into the aquarium.

There is one in particular however that in my opinion is more decorative and ‘standard’ live rock.

Tonga rock

Tonga rock is different to other types of live rock due to the reason that it looks like branches of a tree. It can be an extremely decorative addition to a saltwater aquarium. Due to tonga rock being thinner and not boulder shaped like the majority of other live rock with the obvious exception of plating rock you have the ability to be able to create fantastic water movement around it.

In my opinion tonga rock is fantastic for SPS corals as you can provide a large amount of water movement and if carefully aquascaped can look amazing. This is not to say that you could not have a fish only aquarium or a soft coral aquarium with tonga rock as you would be able to. You would just have to bear in mind that you will need to create caves etc for the fish to hide in as well as creating ledges to place the soft corals on.

But what about the filtration – is tonga rock as good as other live rock.

Tonga rock does have good filtration capabilities however they are not as good as other live rock. This is mainly due to the size of the physical rock. To purchase enough tonga rock to faciliate the filtration requirement would make it very hard to aquascape.

So what do you do?

In my opinion it is quite simple. I personally would use the tonga rock for decorative purposes and then have an in tank deep sand bed as well. The deep sand bed would be the main aspect of the filtration but the tonga rock would do some as well albeit reduced. You do not need to have the deep sand bed in the display aquarium it could be in the sump in the cabinet. You would just need to make sure that the partiton designed for the deep sand bed was large enough.

One of my dream aquariums (we all have them don’t we) is to have a 3 foot cube tank (3*3*3). In this aquarium a deep sand bed would be placed and tonga rock used for decorative purposes as well as some plating rock to provide some hiding places/ledges. Lighting would be provided by metal halides, the water movement would be chaotic and my corals of choice would be SPS with a small amount of fish.

We can but dream can’t we?

---

Is There Such A Thing As The Best Aquarium Filter?

Filtration in the marine aquarium supports the number one requirement, and that is water quality. Whether the system is a fish only aquarium or reef aquarium, water quality is paramount. The next most important requirement is lighting for a reef aquarium.

The question here is a little too general. Are we talking of bio-filtration, or is it mechanical and chemical filtration? I don’t know what was behind the question so let’s have a look at them all.

Bio-filtration is the major filtration need in an aquarium, so let’s start with that. Bio-filtration is where the nitrogen cycle, or part of it, takes place. That is, bacteria take dangerous waste such as ammonia and nitrite and convert it. Without this natural service keeping a marine system of any type would be difficult, expensive and not so good for the inhabitants.

The major requirement for bio-filtration (at least the initial stages of the nitrogen cycle) is oxygen. So for anything to operate well this oxygen supply is required.

The first method with this in mind is the trickle tower, where water runs down with gravity through media. This is a good method of filtration, as oxygen is readily available from the atmosphere. The bacteria are not going to have any problems. The downside is that these filters produce nitrate and that point is the end of the nitrogen cycle.

So what about that old and well trusted method, the canister filter. These filters are very reliable and the modern ones are easier to service (this used to be a bind). The bacteria are completely submerged and depend on oxygen from the seawater, so it is important for the system designer to bear this in mind, that is the water surface should be open, and in addition if possible weirs should be incorporated, or a powerhead could be directed at the surface. Additional oxygenation may not be needed in a well designed system with correct water movement. Again, the end product is nitrate.

The under gravel filter is subject to the same oxygen considerations as the canister. However, the under gravel filter is, at least in my opinion, not a good choice because of eventual problems with media blockage. This filtration will not be considered further.

Though there are other bio-filtration methods the last one to be considered in this text is live rock. Live rock is natural in that it is nature’s product. The bacterial process in any filter type is natural of course, but live rock is natural overall. Live rock in sufficient quantity and of high quality can successfully filter an aquarium. A big plus is that this method can deal with nitrate if not abused – in other words, the filtration provides the full nitrogen cycle. That is a big plus. In addition, the very fact that it is rock means that the aquarist can use it to aquascape the aquarium, and it doesn’t matter if the system is fish only or reef. The bacteria again rely on the oxygen in the seawater, so the points noted about this are relevant.

It doesn’t take a detective to discover the champion bio-filtration system here, and yes, it is live rock. The downside is that live rock is expensive, and corners should not be cut to save money with this filtration. If money is a problem, then consideration to the canister and trickle methods can be given, remembering the point about nitrate.

Right, that’s that bit covered. What about mechanical/chemical filtration? There’s not much to be discussed here.

With this filtration the aquarist requires a method that is unobtrusive and reliable. There aren’t any oxygen considerations. The canister filter is the one, and ideal for the job. They usually have compartments where different media can go – sponge of various densities and other fine filter types to trap detritus, and carbon if used. As said, canisters are easier to service nowadays than they used to be and that is the main requirement – they should be regularly serviced and any carbon changed, and detritus trapping media cleaned or renewed. The cleaning can be under a tap, there isn’t any need for caution in respect of bacteria. (Note that this is mechanical/chemical filtration. If a canister is being used for bio-filtration then cleaning under a tap the media supplied for the bacteria is a no-no, as the bacteria will be killed with dire consequences.)

So there we have it, the best: live rock for bio- filtration and canisters for mechanical/chemical filtration. This is of course my opinion, but I would hazard a guess that there aren’t many who would disagree.

---

Can You Add A Deep Sand Bed To An Existing Setup?

Every week I like to pop into my local fish shop, even if it is not to purchase something just to have a look about and have a chat with the owner.

Over the years we have built up a bit of a friendship and over a cup of coffee we tend to sort the world out – both aquatic and non aquatic related!

Anyway whilst I am in there other people of course come in and ask various questions, purchase things and I like to keep out of the way whilst this is happening. I normally go and look at the corals and fish with my cup of coffee in hand.

Yesterday whilst I was there I overheard a conversation between a customer and the owner of the store entailing deep sand beds.

It is probably obvious by now that I am a huge fan of deep sand beds.

Basically the customer had heard that you cannot add a deep sand bed to an aquarium system which is already setup and the owner of the store was patiently attempting to explain to him that it was possible to do so.

The conversation did not get heated but to cut a long story short the customer would not take any advice from the store owner (the expert if you will) and left the store. As far as he was concerned this is what he had been told so it must be right!

It must be very hard for owners of shops, not just fish shops but any shop for that matter to deal with situations like these.

We chatted about it afterwards and he said that although it is hard he will not tell anyone incorrect information even if it means losing their business. It is not just about the money he earns but the love for aquatic life which he sells.

To be honest what he was discussing with the customer was correct and I thought that I would cover it here in case any readers of Aquarists Online have been wondering about this as well.

If you are interested in understanding more about deep sand beds then click the link below :

http://www.aquaristsonline.com/blog/aquarium-filtration/the-deep-sand-bed-one-of-the-most-effective-filtration-methods/

The above article covers how a deep sand bed works, the importance of grain size etc etc.

What we will cover in the remainder of this article is the introduction of a deep sand bed into an existing aquarium system.

It is presumed that you have purchased sand which is of the correct particle size.

I would advise that any sand purchased is cleaned thoroughly in saltwater. The saltwater removed from the aquarium when you do a water change would be fine for this use. An even better way than just washing the sand is to leave the sand covered in saltwater for a period of a couple of weeks.

Some aquarists even run a magnet over the surface of the sand just in case there are any metals in there but this is not a definite requirement.

Once the sand has been prepared you are now in a position to be able to add it to your aquarium.

If you have any sand in your aquarium and it is not of the correct granular size then it will need to be removed from the aquarium. Do not discard it though as you can use some of it to ‘seed’ the new sand bed.

If you have any sand in your aquarium and it is the correct size then it can be left in the aquarium, however do not be tempted to add all of your new sand in one go – add it slowly over time. The reason for this is that when you add new sand the life which lives in the existing sand needs to move higher up in the sand bed and if you put to much in at one go then you may kill them.

Due to displacement some water will also need to be removed from the aquarium.

Turn the pumps/powerheads off in the aquarium and slowly add the sand to the bottom of the aquarium.

Do not be tempted to lift any of your rocks off the base of the aquarium simply add the sand around the rocks.

If you did lift the rocks off the base of the aquarium and then place them back on top of the sand then this would cause compaction in the sand and the bed will not function.

With you adding the sand around the base of the rocks compaction can occur and more importantly the little beasties can migrate from the rock into the sand. It is important to have a huge diversity of life within the sand bed as they consume the detritus in the bed as well as ‘turning over’ the sand.

The pumps/powerhead can now all be turned back on again.

With you having a running aquarium system then you will no doubt get a sand storm in the aquarium. This will clear quite quickly.

Once the bed is in place if you removed and old sand from the aquarium then some of this can be placed on top of the new sand bed as this will help introduce the valuable little creatures into the bed.

Your job now is to feed the bed to ensure that the population grows and grows. Regular feeding will be required and can be achieved by simply placing a cube of frozen food daily on top of the sand bed. The food can be held in place by a stone, shell of something similar. Vary where you feed the bed and over time the population will increase and before long you will an exceptionally powerful filtration device – especially if you combine it with live rock.

I suppose that there is also a moral to this article as well as some information being provided in relation to the introduction of a deep sand bed.

The moral is that you are not always right. Listen to what other people have to say, take their advice and then make your own decision.

---

Why Does Sand Become Such A Detritus Trap?

Not all marine aquarium systems use sand. These are said to be ‘bare-bottom‘, and the aquarists have decided to forego a sand bed in the interests of cleanliness. When the aquarium is new, the bare bottom does look unfinished, but in a little time if the seawater conditions are correct the bottom is covered in different algae, and this can look very attractive. Note this is not the often persistent nuisance algae, but decorative types.

I would hazard a guess that the majority of systems have sand in. This can be either decorative sand or a deep sand bed (DSB) or plenum (a raised DSB).

The sand used on a DSB is of fine particles, and dirt that reaches its surface has a tendency to sit there. Eventually it is utilised by the tiny life forms that inhabit the area. Some may penetrate a little way but not a lot and not very far. These beds are around 4″ deep or more.

If the sand is used for decorative purposes only it is placed in the display aquarium and covers the base. The sand is usually coarse and makes a very attractive addition to the aquarium. These beds are often up to 1″ deep.

The reason the sand becomes dirty is mainly because of the size of the grains. In the DSB as stated it is fine, perhaps it could be described as very fine. If a fairly strong water current hits it  a cloud can be raised. Though problems can arise with a DSB, with proper construction and sufficient life it is not usually dirt penetration.

The coarse sand of the decorative sand bed is a different story. Fish faeces, bits of food, dead algae and other general rubbish can fall to the bed. It breaks down and falls between the grains. The grains are coarse enough to allow tiny dirt particles to follow the ’channels’ formed by the spaces between grains. Enough of this dirt can cause the sand to become clogged. This was a major problem with the under gravel filter of yesteryear, which pulled water down through coarse sand and the dirt with it.

With a decorative bed the way to prevent this is to stir the sand frequently with a clean stick. The stirring can be reasonably vigorous and is best done at the time a routine water change is performed. This allows the aquarist to stir the sand and follow the stirring stick with the intake of the water hose, removing dirt. There isn’t any need to do all the sand bed at once, just a proportion at each change. The aquarist can become very expert at this job.

A DSB should never be stirred or the disturbance can spoil the filtration capability of the bed. As said, a well made DSB will possibly look scruffy but should never become really dirty.

It is important to stir a decorative sand bed routinely as described as it prevents the bed from becoming really dirty, which would make the cleaning job much more difficult. If the bed is really very dirty, it would probably be best to siphon out a proportion of the bed at each water change, thoroughly rinse it, and then return it. Routine stirring will prevent the need for drastic cleaning and maintain the attractive appearance of the display aquarium.

---

Deep Sand Bed Construction

The construction of a deep sand bed (DSB) is very simple and straightforward with only a few requirements.

Many marine aquarists undertake this job as they wish to maintain high water quality and at the same time have additional interest in the aquarium, which takes the form of the tiny, and sometimes not so tiny, life forms which hopefully will make the DSB their home.

Dr Ron Shimek is a very well known aquarist who undertakes research. Following is a link which provides all the information needed – sand type, depth etc – in the making of a DSB. In addition, some of the life forms that may inhabit the sand are given. It is very well worth a visit if a DSB is being considered.

http://www.ronshimek.com/Deep%20Sand%20Beds.htm

---

Old Tank Syndrome – Update

A while ago my reef showed clear signs of a sizeable reduction in the tiny creatures that inhabited the deep sand bed (DSB) and also the reef rocks. I noticed this most at night. I wondered if this might be the so called ‘Old Tank Syndrome.’ See ‘Old Tank Syndrome‘

The maintenance regime on the [tag-tec]reef tank[/tag-tec] was maintained without change, including feeding of the DSB. I watched very carefully, particularly at night as this is when most activity occurs. As the population of the [tag-ice]deep sand bed[/tag-ice] had reduced so much I kept a very careful watch for signs of pollution (was anything eating the food?). There was no real change at all, although the occasional beast was seen. There wasn’t any visible evidence of pollution.

Three nights ago I went to the [tag-self]aquarium[/tag-self] not expecting to see much. I’d accepted that for some unknown reason the beasts had reduced considerably in number. To my surprise, there was a fair amount of activity. It wasn’t as I am used to, that is it didn’t look like a shopping precinct on a Saturday afternoon. However, it was clear that the minute life had increased.

This increase in life forms continues. I continue to watch at night mainly.

I cannot give any sensible reason for the reduction and the increase. Maybe predation reduced the numbers because of unsustainable predator increase. Then maybe the predators reduced. Then maybe the surviving life forms were able to re-build their population. I don’t know. It seems the occurrence was a natural one, some kind of cycle?

The main thing is, they are back with rising numbers. Once more it goes to show that on occasion time must be given for nature to do her thing.

---

« Previous Page — Next Page »