Dear Mr. Goemans,
Could you please help me with the problem that has plagued my tank (100 gal) since it was set up in July. I have this gelatin like substance that covers all the rock and the back glass. It has a light tan colour and in places it has air bubbles attached, which cause it to form vertical strands. I realize the tank is still breaking in but the live rock is from a tank that was about nine years old. I had this same problem in that tank so I figured that by cleaning the rock with a tooth brush and then putting it in a new tank which has new substrate on the bottom I could hopefully cure the problem. However after being set up for a few weeks the problem was back. The new substrate is aragonite gravel of the size recommended on your website for use in the jaubert method of filtration. It is about 1" deep in the tank. The 4" deep bed is located in a separate tank. There are no fish in the tank and just a few soft corals that were moved from the first tank. Therefore the bio load is quite low. The water quality is as follows:
nitrate 12ppm
calcium 400
I have been adding buffer for alkalinity but I seem to be having trouble getting it into the recommended level. It is sitting at about 2.4 meq/L. The lighting is provided by 4X4 VHO florescent tubes.
Many thanks
Robert Barlow
It sounds like a dinoflagellate type situation, not a diatom problem. It can result in large areas, including invertebrates coated in a brown slime-like gelatinous mess. This free-swimming algae, which came in on your rock, is difficult to cure. The reduction of the photoperiod, especially when using metal halide lighting is sometimes helpful, as is ceasing to add trace elements. The use of ozone and/or a UV sterilizer is also helpful. I have found that flowing all aquarium water through a sponge filter, which should be cleaned twice a week, is also helpful. Silicate is not a growth nutrient for this type algae as it is for diatoms. Unfortunately calcium carbonate is. Since we can not rid the aquarium of its calcium carbonate content, we need to concentrate on the above methods for ridding this pest. If you have a small microscope, you can tell which form of brown algae you have. If the algae cell has a small tail, it is the dinoflagellate type.
I recommend siphoning it out as often as necessary, adding an ozonizer to your set up and discharging the ozone into your skimmer. Red Sea makes a nice ozonizer unit. If you're not familiar with how this works, either read my booklet on Protein Skimming and Activated Carbon or contact me again and I'll explain it. However, have about 100 unanswered emails in front of me today!
And honestly, using separate buffers and/or calcium additives is really detrimental to maintaining good water quality. There's a complete rundown on how to maintain all water parameters in my Water Quality Guideline booklet. And I'm not trying to sell booklets, but have put most of the answers on how to resolve these problems in very inexpensive booklets with no advertising hype. Just plain English. Those booklets are mentioned on my website - www.saltcorner.com.
Cheers,
Bob