Saltcorner
By Bob Goemans
By Bob Goemans
Dear Bob,
After a 16 year absence from reef tanks I finally have the opportunity to return to my mistress, marine aquariums. I have read your column in FAMA for over 2 years now. I have also read some of your booklets and The New Wave as part of my research on new developments since my introduction to reef systems by George Smitt in about 1985. Is it that long ago?
Your books and column have answered many questions about why I experienced failures with my mini reef system but I have two questions that remain unanswered.
1. You have constantly stated that improper use of carbonate buffering and use of calcium result in a build up of calcium phosphate that acts as a nutrient source for algae and binds the substrate. The message is clear and I understand the problem but in your writings you have not articulated what is an appropriate use of calcium and buffering additives. Perhaps you could share your experience in this area and recommend an appropriate approach to testing and buffering.
2. You have often stated that the ideal start to a reef aquarium is to use live sand. Unfortunately live sand is not available in Australia. The best we can hope for is a few cups full of substrate from an established tank. Perhaps you could make recommendations on the best way to cycle a new tank using dead sand and the best way to stage the addition of live rock.
Thanks for your valuable insights to successful marine aquariums.
Gary Solomon
Sydney, Australia
Dear Gary,
Thanks for your letter and you think the George Smitt timeframe was far back. I had my first marine aquarium in 1956!
There's no doubt the precipitation of calcium will take phosphate with it. Whether its with the use of Kalkwasser, improperly used buffering and calcium additives, or simply the misguided thought that reef systems need far higher amounts of calcium than exist in natural seawater. In some ways, the removal of phosphate is very helpful in preventing unwanted cyanobacteria or unwanted algae blooms. Whether or not these precipitants ever reenter the bulk water has led to much conjecture over the past years.
As for phosphate, most comes from food that is fed the fishes, with the quality of the tap water used for evaporation makeup or water changes another very possible source. Yet once phosphate is precipitated and bound to calcium, it is unlikely it will ever reenter the bulk water as it is quite stable and will not be reduced/oxidized unless subjected to a very low oxygen content, such as what can be found in an anaerobic zone. As unlikely as that is from happening, precipitated calcium phosphate could be on the surface of some live rock and if covered by a cyanobacteria mat or algae mat, it could then be subjected to that low oxygen content. If so, it may become oxidized, releasing the bound phosphate and encouraging a further bloom of unwanted bacteria or algae.
When it comes to binding of sand grains, precipitation and quickly forming bacteria colonies are two reasons why sandbed clumps form. Whichever may be the cause, it behooves the aquarist to survey the sandbed occasionally, probably once per month, to be sure the bed grains remain loose and have not began to solidify. Once the sand becomes hardened, it loses its ability to act as a biological filter. Actually, no different than a dirty filter pad where water now flows around it instead of through it!
In my opinion, the goal in reef systems should be to maintain calcium levels near what it is in natural seawater (400 ppm). In fact, I've found that something in the range of 380 - 430 ppm is quite adequate for our reef systems. And that can be accomplished with either a calcium reactor or if that piece of equipment is outside the budget, a two-part liquid calcium and buffer product. In fact, I'm currently using the ESV two-part solution in my new 60 gallon reef system where pH (8.0 - 8.1), calcium (420 ppm) and alkalinity (12 dKH) are right where I desire it.
As for the use of separate powdered buffer and calcium additives, in which one is used to solely raise pH 'or' the calcium level when either appears low, they are in my opinion sometimes detrimental to the stability of the chemical environment in the bulk water. I say detrimental not because they are inferior products, but because they are 'often' improperly used. In fact, this whole subject (calcium & alkalinity) is covered in depth in one of my booklets where it alone encompasses about 6500 words.
I know Australia is highly restrictive when it comes to the import of many aquarium products, especially chemical/food additives. Yet, I would tend to believe there must be some starter additives in your area that encourage the nitrification cycle. These products will help reduce the cycle time of any new aquarium. Yet, a cup of active gravel/sand from a healthy aquarium will also do the same thing.
As for the use of new uncured live rock, my preference is to first place the needed amount in a clean plastic container similar to a trash/garbage can and cycle it for about ten days. Place a pump in the container for water movement, and if possible connect a protein skimmer to draw-off some of the liberated nutrients. The nutrients from the new rock are far better in the holding/curing container than your aquarium!
Of course, the sandbed with a starter additive or a cup of starter substrate from another aquarium can begin before the addition of the live rock. Once the rock is initially cleaned of most of what would die-off and add nutrients to the aquarium it can all be added to the aquarium. If the newly purchased live rock is already cured, it could be added on the same day the sandbed is installed. As for 'staging' the addition of live rock, that would be necessary if you were adding fresh, uncured live rock. If you did not have the capability to cure the rock, then one or two pieces of uncured rock could be added to the new tank when first established. Then, over the coming months add small amounts of uncured live rock until the basic reef structure is completed. However, this requires great patience, which some aquarists don't have when starting a new system. And, the die-off from that uncured rock needs to be addressed in the new system as necessary, i.e., siphon out any loose debris and/or detritus that is collecting in areas, and replace with newly prepared seawater.
I hope this is helpful and keep me posted.
Cheers,
Bob
