Simulating Fish During A Cycle

[P&J]

Question about a fishless cycle:

I understand that a fully cycled tank can process approx. 4ppm of ammonia in about 12 hours, but in reality, fish don't just dump a load of ammonia in the tank every 12 hours. Theoretically, if you could set up a slow-release ammonia system (similar to an IV, for instance), is there any way to determine how much would simulate a fully stocked tank? Would it be as simple as using enough ammonia to raise it to 4ppm but slowly distributing it over 12 hours?

-P

 

[rdd1952]

I'm sure you could calculate how much ammonia fish produce in a period of time, say a day. You would also have to figure in uneaten food and plants or other items that happen to decay. As you mentioned, fish don't just dump 4 ppm of waste in a tank all at once. The problem with an IV/time release method is that you are staring with no bacteria at all, so when you first start adding the ammonia even via a drip, it will probably still build to the 4 ppm or more before any is ever processed. After that and once it dropped back to zero, the bacteria would be processing it and probably keep the ammonia at zero but the nitrite would start to build because there is no bacteria to handle it. It would have to go through the same process.

That method does sound as if it would have some merit though. I feel sure it would work. After all, not only do fish not just dump 4 ppm at once but they probably don't produce that much in a day. We are building a bacteria colony that can safely handle a full fish load immediately so we are looking for overkill so to speak. We don't really care that we have too much bacteria and some of it will die off, we mainly care that we definitely have enough so we don't have a problem. It may also keep the nitrite level from getting so high and thus speed the final nitrite drop. It would be an interesting experiment to see how well it worked.

 

[P&J]

I'm sure you could calculate how much ammonia fish produce in a period of time, say a day.

That's where I'm stuck though, I don't know how it would be calculated.

I agree with you about building to 4 ppm anyway in the beginning, but what I'm really looking for would be used mid-cycle. I think a system like this, if feasible, would be perfect if you are unable to add ammonia for a day or so (out of town for a weekend, etc.) or if you want a "set it and forget it" cycle.

Could you set up something like this and let it run for a few weeks on its own? Or could it help you out mid-cycle so your bacteria doesn't die? Has anyone tried anything like this?

-P

 

[rdd1952]

About the only way you could do it is set up a tank without a filter and monitor the rise in ammonia. I would think that the systemwold work best at mid cycle so that the ammonia goes in slowly but that's purely a guess. It may not matter at all in the over all time it takes to cycle. After all, the end result will be the same amount of ammonia going into the tank and thus the same amount of bacteria needed to process it although it could be a little less since the ammonia is entering at a slower pace. I don't think it would make more than a day or two difference in the total cycle time.