Cycling nonsense

[kreblak]

I am currently fishlessly cycling a 10 gallon tank. All that sits in the tank is a 3" DSB, a heater, a rotting shrimp, a thermometer, and an aquaclear 201 powerhead. I have been cycling for three months!

My water parameters stand as thus:

ammonia = 3 ppm
nitrites = 0
Salinity = 1.023
temp = 79*
pH = 8.2

These readings have been conducted on a Salifert test kit, as well as a Tetra test kit, in triplicate. All tests show the same results. My LFS has verified my readings as well. Further, these readings have been consistant for the last three weeks!

The only explanation I can think of is that the shrimp (which is still in there after three months) is producing too much ammonia for a 10 gallon tank to deal with. My nitrites have been zero for a long time now, so maybe there is just too much ammonia. I am wondering if I shouldn't remove the shrimp and call the cycle finished, as the biofilter has had more than enought time to build. Any thoughts?

[a_free_bird73]

You did not mention anything about Nitrates. If the concentration of Nitrates is increasing and you are still seeing traces of Ammonia, then it is a sure sign that the biological filtration (probably only in the sand unless you have a sponge on the powerhead) can't cope. If you either increase the size of your biological filter (bigger sponge or something) or remove the shrimp, you will probably see your ammonia disappear within a couple of days...

[Guy W]

Other than the sand bed do you have anything else for filtration at this time? I.E. do you have live rock in there yet? A sand bed alone probably won't hold enough bacteria to denitrify your tank.

I would recommend adding 10pounds of base rock or uncured live rock, and leaving in the shrimp for another 2 weeks then check your numbers. When the level out add another 5 or 10 pounds of premium cured live rock and you'll be set I think.

Guy

[kreblak]

No, I don't have any rock in the tank yet. Just sand. Does zero nitrites mean that my biofilter has grown to capacity? Basically, has my bacterial bed grown to the point where there is nothing left to colonize, so the nitrites get dealt with just as quickly as they are produced by the ammonia ingesting bacteria, but there simply aren't enough ammonia eating bacteria to deal with the shrimp's ammonia output?

[Guy W]

Originally posted by kreblak
No, I don't have any rock in the tank yet. Just sand. Does zero nitrites mean that my biofilter has grown to capacity? Basically, has my bacterial bed grown to the point where there is nothing left to colonize, so the nitrites get dealt with just as quickly as they are produced by the ammonia ingesting bacteria, but there simply aren't enough ammonia eating bacteria to deal with the shrimp's ammonia output?

I'm not an expert but that does sound logical. Are your Nitrates really high? Thats another thing you should check that would help back up your theory. If they are then the Nitrosomer something-or-another bacteria are turning Nitrite into Nitrate fast enough, but ya I would assume the other kind of bacteria aren't turning the Amm. into Nitirite fast enough.

Guy

[kreblak]

Guy, I just realized after reading your last post that I never posted my nitrate readings. :rolleyes: They started off really high three weeks ago, but have been steadily decreasing since. My last measurement came in at 10-20 ppm.

[a_free_bird73]

I have done capacity tests on biological filters several times and yes would be the most likely answer. Your sand bed has reached its processing capacity. Adding rock will increase the capacity, but that depends on what you are going to use the tank for!

[kreblak]

Good! The shrimp goes immediately. I'm tired of looking at that rotting piece of nastyness anyway. :D