Saltcorner
By Bob Goemans
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Bob Goemans corresponds with Bubba

Bubba writes...

Hi Bob,

I currently own a 10 gallon tank that is culturing live sand for my 125 gallon tank when I can afford some lighting. My problem now is nitrate at 12.5 to less than 2.5 parts doing Bi weekly water changes of 3 gallons. When I set up the tank I was talked into using a five gallon undergravel filter with a 201 AquaClear powerhead on it. I also have an additional one for cross circulation, also I have a Millennium 1000 back pack for surface agitation. I also use a carbon insert and the air valve in the filter. The substrate is a 50/50 mix of aragonite and crushed coral. In the tank are two green chromis, four snails, four blue leg hermits, one brittle star (burnt orange in color with black patterns on body and stripes on arms) unsure of name, also several small brittle stars as sand stirrers (they are tan bodies with white arms with black stripes). The store I bought them from in some live sand does not know what they are or if they are reef safe. I read in last months Sand Mail your disaster with sand stirrers and was curious about these.

But could my nitrate problem be in the stocking of the tank or the under gravel filter or something else? I would appreciate your thoughts. I also just received your booklet Live Sand Secrets and will be utilizing it for my big tank. Next will be the Water Quality Guidelines for Marine Aquariums.

Thanks for your help

Bubba

Bob replies...

Hi Bubba,

Actually, the nitrate level is what I would call quite normal for this small system and its bioload. Reducing its level (nitrate) is probably not going to happen for numerous reasons. Even though you say there's an UGF in use, you don't tell me the depth of the bed, or the physical size of the grains. And that has a direct bearing on the biological processes occurring in the bed. And besides, the end result of UGF, trickle filters ,and fluidbed filters is 'nitrate.' That's to be expected! How much accumulates in the bulk water depends upon the efficiency of the bed, general bioload and system cleanliness. Water changes can help in small systems, but even that becomes less than cost effective as the system ages.

For right now, stay with water changes. If nitrates get a lot higher, say over 50 ppm, then contact me and we'll take steps to correct it. But for now with the present bioload, I wouldn't be too concerned.

As for the so-called sand stirrer, it was one of my biggest mistakes to put that in my reef system! It simply ate all my good worms and crustaceans that helped keep the sand functioning. It's called Archaster typicus. Not truly an ideal animal for our sandbeds, unless they are very shallow and mostly there for looks.

Hope this helps and keep me posted,

Bob

Keywords:

Undergravel Filters; Sand Stirrers

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