Saltcorner
By Bob Goemans
By Bob Goemans
Dear Mr. Goemans,
I am in the process of starting up a 75 gallon reef tank and I am wondering if you could please answer a few questions. I have been trying to do as much research before starting and have read your booklet 'Live Sand Secrets' as well as John H. Tullock's Natural Reef Aquariums. There are a few points that I am unsure of when starting the system, especially when dealing with the plenum. You recommend using aragonite in the first 1 - 2 inches where Tullock indicates that it may eventually turn into chunks of concrete. I understand that you recommend using a dull knife blade to occasionally run through the sandbed, but can you get down far enough in the bed (through the screen) to break up the lower level?
Also, Tullock recommends using enough ammonium chloride solution to give 3.0 ppm on an ammonia test kit when the live sand is first added. I am assuming that he is attempting to help in the nitrogen cycle before any live rock and sea life are added. You recommend using a starter culture made for aquarium. Is this essentially doing the same thing?
Finally, several months ago you wrote about calcium reactors in your monthly Sand Mail. Could you please recommend one for me for my size tank.
Thank you for all your help and time.
Jason Isely
Plains, PA
Hi Jason,
Thanks for your letter. I have yet to see clumping under the dividing screen, however, it may occur but am not yet aware of it. Usually, its something brought on by either improper dosing of calcium and buffer additives where excesses precipitate and bind soft substrate particles together or fast forming bacterial colonies, especially in the upper layers. Binding always seems to appear to take place from the surfaces grains downward, therefore, it's why I recommend checking the substrate at least monthly. Whichever is the cause, ongoing substrate surveillance is necessary, whether it is in a plenum system or a deep bed (DSB) directly on the aquarium bottom as I've experienced binding in both types of beds.
Furthermore, the dividing screen can be encompassed somewhat in the formation of these clumps if the condition becomes prevalent. Not using a dividing screen is becoming more popular as is an interconnected auxiliary plenum system.
As for aragonite, it's one of the best substrates for reef systems, yet other forms of calcium carbonate can be used, e.g., crushed coral. The most important aspect of substrate material used for plenum systems is its grain size. And it's not necessary to use different types or grain size material to make the bed. One type of material, with a grain size of about 2 - 4 mm, will result in a bed having excellent diffusion capabilities.
The use of ammonia chloride is what's termed the 'inorganic' approach to establishing the nitrification cycle. It works well, however, nothing alive can be placed in the aquarium while the system is cycling. So that delays putting anything alive in the system for about four weeks. Generally, most hobbyists use the 'organic' approach, which includes the use of some live rock/live sand to supply the needed bacteria. If the inorganic approach was used with live rock, it would kill much of anything living on or in it.
Of all the helpful starting cultures that I've used for beginning new systems , I've found the Marc Weiss Bacter-Vital one of the best. This product appears to do more than just hasten bacteria growth, as it is my understanding it also helps balance the nitrogen/carbon ratio in the new system. This is extremely important to beginning with a balanced microbial system. Because of this it's often my choice as a starter product in my tanks and client systems.
As for a calcium reactor, I have suggested some brands in my return letter that I have personally have excellent results with.
Hope this helps,
Bob
Hi Bob,
Thanks for responding to my e-mail. I did have some additional questions regarding plenums that I hope you can answer. I would like to set up an Auxiliary plenum using a 55 gallon tank (the main tank will be 75 gallon). I know the recommendations are to typically run about 25 - 30 gallons/hr through the auxiliary. If this is the recommended flow rate, do you suggest continuing to use a sump and pumping water through the auxiliary using power heads? If I was to place the plenum in the main tank, and follow the recommended water turnover rate of 4-6 times/hr, why is there such a dramatic difference in rates between the main tank/auxilary plenum?
In your book, Live Sand Secrets, you recommend using a few small pieces of live rock in the auxiliary system. Should there be any special consideration for lighting? Also, should I use live sand in the main tank and if so, how much? Finally, with regard to activated carbon, I have used chemipure/polyfilters when keeping fish only systems. Have you ever used these products and do you have any other recommendations? Thanks again for your time. I like your web site!
Jason Isely
Hi Jason,
As for water flow through the auxiliary plenum, that is usually a smaller system than the main show tank. It does not contain any corals or fish, and slower water flow simply allows for more 'dwell time.' In the main system, the dwell time is automatically there since the water is not going to another tank for biological filtration. And flow rates in the show tank have little to do with what's occurring in the sandbed. The flow rates in the show tank are higher for the benefit of the animals, not the bacteria.
If the auxiliary plenum system is used solely for filtration purpose, no lighting is required. I turned my auxiliary plenum into a sponge tank. If you want to use it as an oppositely lit refugium with some small creatures and as a slight pH and alkalinity boost for the main system, use common household fluorescent lamps.
As for ChemiPure/PolyFilters, have used both and they are excellent products and would continue their use in your marine system. Hope this helps,
Bob
