We’ve Created Some Test Charts To Assist You
October 17, 2008
Aquarium maintenance is a necessary job, one which keeps the marine aquarium looking as good as it should with all the livestock healthy. Some aquarists enjoy it, some don’t.
Keeping a notebook to remember those items that need to be done from time to time is a very good idea – when the lights need changing, or the anti-phosphate media, or activated carbon etc. No matter how good the aquarist’s memory is, when months pass between some actions a reminder is useful.
Another advantage when keeping notes is with seawater testing. In the early days of the aquarium, the aquarist will not be sure of the trends. For example, calcium will be depleted at a generally given rate. The demand from the aquarium may be high or it may be low, but it is very useful to know it. So when testing calcium if a note is kept at each test, then over a period of time a trend will appear, and the aquarist can see the rate of decline of the calcium level, which of course will cover routine seawater changes that are completed. So dosing of the aquarium can be accurate, using an additive or an automated device. Then again, look at pH. It is important that, within bounds, the pH is stable. Tests may throw up differences that on their own are generally meaningless. However, if a note is made each time a pH test is completed then again a trend could be seen. Maybe the pH is 8.3 when the lights are on, but on occasion the aquarist notices that it drops to 8.2 or perhaps a bit lower when a test is done early. During the dark period seawater does often have reduced pH then when the lights are on again it rises. Within limits this is acceptable, and with notes the aquarist can see what is happening and how much variation over what period occurs.
Later in the aquarium’s life the aquarist may decide to reduce the frequency of testing. This is fine if the aquarist is confident that seawater ‘habits’ are known. Tests still need to be done however even though less frequently, and a note of the results can be made for future reference. If a very slow decline is happening then the aquarist will see it. If a problem arises, logging down test results will show the effectiveness of any remedial actions taken.
We have produced some simple charts so that there isn’t any need to even purchase a notebook. Just download whatever is needed, as often as is needed. Not every aquarist needs the same tests, for example fish only aquariums only need 3 or 4 whereas reef aquariums need more, and the charts are adaptable as required.
Phew! What A Smell
June 8, 2008
Every time I sit and gaze at the aquarium, the gazing interlude is preceded by a visual glance at the main equipment – heaters, skimmer and the like. I also do this just before I feed, it only takes seconds and becomes second nature.
So there was I, defrosted brine shrimp ready for the fish, and my eye wandered around the aquarium equipment as usual. What attracted me to it I don’t know. I’d not noticed it earlier.
In the back bottom right hand corner it lurked. Dark and threatening and definitely not wanted. Some beast that had crept out of the rock?
No, much more simple than that. It was a patch of smear algae, sometimes called blue-green algae (which makes it sound quite pleasant, but it isn’t), also called Cyanobacteria.
This unpleasant stuff likes areas of low seawater flow, and sure enough it was in such an area. It also needs nutrients.
Out came the phosphate (PO4) and nitrate (NO3) tests. The tests showed ’undetectable’ for both. Perhaps there is a trace in the seawater but the tests aren’t sensitive enough?
Anyway, somewhat reassured, I removed the stuff with a stiff toothbrush. That’s about all that can be said for it, it isn’t particularly difficult to remove.
If there is any nutrient, why is it not being controlled? The skimmer operates as usual. All pumps etc are fine.
Then I noticed. I’m not sure if this is the reason, and if it is it seems a little illogical.
The drip rate from the output of the sulphur denitrator was exceedingly slow. One drip every few minutes! How could I have not noticed!
Anyway, I decided to clean the denitrator and ensure it functioned properly. I remembered the ‘nil’ reading from the nitrate test, but this must be because of the live rock. The pump was stopped and all feed/exit pipes disconnected. The tube containing the sulphur beads was taken into the kitchen.
I took off the sealing plate at the top of the tube and started to pour out the seawater. Wow! The smell was incredibly horrible, like rotten eggs that weren’t satisfied with being rotten and so double rotted. Yuk.
With this lovely un-aromatic stench around my head I emptied the tube and cleaned everything. All windows and doors were opened (good job it was a sunny day) causing my wife to come in, attracted (no, that’s got to be the wrong word) by the smell. An explanation was given, and she didn’t hang about but went back to the sweet air of the garden. The smell hung around the house for ages, even though fresh air had been given entry.
The problem, of course, was hydrogen sulfide, which gives itself away by the very distinctive rotten egg smell. The flow of seawater through the denitrator had been so low that the hydrogen sulfide had the opportunity to develop.
The denitrator was set up again, and I was about to switch it on and begin the process to re-establish the bacteria. Then I stopped and closed the flow taps.
There wasn’t a reading of nitrate on the test. The rocks in the aquarium are live. So why use the denitrator? The live rock must be doing its job.
I’ll have to monitor for nitrate regularly for a while, just in case the denitrator had taken any load off the live rock – perhaps the live rock will need to get up to speed.
So why is there a denitrator present anyway?
The answer is that when the aquarium was started 5½ years ago, the rocks that I used weren’t live. They were inert and highly porous, and over a long period they have developed into live rock – the holes, crannies and surfaces becoming the home of many tiny marine creatures, including of course bacteria.
So despite the fact that I have an inbuilt routine when feeding livestock or admiring the reef, perhaps the routine had become too rigid.
Lesson learned – I’ll not be caught a second time. I hope.
Water Hardness – What Is It?
April 9, 2008
Water hardness in the marine aquarium is important. The term ‘water hardness’ is maybe too general. It would probably be better to call it carbonate hardness. Another term that is perhaps more recognised in marine hobby circles is alkalinity.
In the sea, the measurement is around 8 dKH (or 2.9 meq/l). This is all starting to sound a bit technical, but it isn’t. All that is really required is for the aquarist to know what the measurement represents, what level should be maintained, and why it is important.
In the sea, there is hardly any change in alkalinity because of the huge volume. In the aquarium it could be a different matter.
Marine aquarium stock carry on with their normal life functions of course. Some of these functions and waste that get into the seawater apply acidic pressure to the seawater. This acidic pressure is constantly trying to lower the pH. (A pH of less than 7 is on the acidic side, 7 is neutral, and above 7 is on the alkaline side.)
As known marine aquariums run from pH 8 to 8.4 for the most part, the ‘perfect’ pH is usually quoted as 8.3. Therefore it can be seen that seawater is alkaline. That’s where it wants to be and where the aquarist wants it to stay. Measuring alkalinity now makes a bit more sense.
Reduction of the pH by acidic pressure is resisted by the alkalinity of the seawater. This is achieved by the carbonate/bicarbonate content. If the aquarist goes to a marine retail shop, there for sale will be additives called alkalinity buffer, pH stabiliser, or something similar. These are carbonates/bicarbonates that are added to the seawater to maintain or increase alkalinity.
The acids that are being added to the seawater are negated by the alkalinity, and the pH is protected against unwanted shifts. However, alkalinity is not constant and can be reduced or even exhausted. As said the seas and oceans are huge, but in an aquarium the acidic pressure could show itself. Routine water changes assist in preventing this. It is considered to be better in a captive system to maintain the alkalinity something higher than natural seawater, and the measurement can be between 9 and 11 dKH (3.2 meq/l to 4 meq/l).
My seawater is maintained at an alkalinity of 3.75 to 4 meq/l. It drifts down during the period between water changes, and is boosted back up (along with the water change). This appears to have assisted in the growth of desirable encrusting algaes and maybe therefore in other life such as snails etc, of which there are many.
Many aquarists do not concern themselves much with alkalinity. This is fine if the livestock is thriving and the pH is as desired and stable.
There are available commercial test kits for alkalinity and they are simple to use. The test kits usually provide a conversion scale to read from, so the aquarist doesn’t have to know what the measurements are scientifically, just what they are of, and the desired level. If an aquarist finds it necessary or just wants to know, this parameter is easily discovered.
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