Cycling a fully stocked tank...

[Screwylui]

i was just wondering if the procedures for cycling a new, sparsley populated tank would be the same for cycling an already fully stocked tank. i guess i was impatient and started adding fish too early, my nitrites still keep on rising occasionaly.

Thanks

 

[Wooster]

well, since there are fish in there it would be wise to make a pwc every now and then. but i have found that only to slow the whole cycle process if one goes overboard with the changes.

 

[RoK]

Well, if it's fully stocked you will get very high ammonia and nitrite levels which will result in fish deaths. You will have to do frequent water changes to keep these levels down but don't touch the gravel or filter media.

 

[TomK2]

Well, can you be more specific? Like, how many fish is sparsly stocked, and for how long did you do this for? What kind of readings did you get with sparse stock? then how many fish did you add, and what readings did you get after that?

the concern is that going rapidly to full stock can result in high ammonia and nitrite just as if you never tried to cycle with low bioload to begin with. This would require intervention on your part, either get some fish out of the tank or become the water change king to preserve the stock you have.

 

[Screwylui]

lol @ water change king. well i'd imagine that the cycle has gone at least half way because i no longer get ammonia readings.. it's just that the nitrites won't get to zero. i don't know if it's the test kit i'm using (hagen) but the test tube is always pinkish.. indicating some nitrites. although i'm thinking that the cycle is getting along slowly because my nitrates are rising to the point where they are higher than nitrites.
right now i've changed my AC 150's media so that it's only the foam insert and then filled it with biorings. do you think charcoal is neccessary?
TIA

 

[Screwylui]

bump ^^^

 

[TomK2]

Na, skip the charcoal. It won't help the cycle.

 

[buggsmarinetank]

I use cycle additives in my tanks, it seems to speed up the process. I also uses a phosphate pad that absorbs nitrite, nitrate, and phosphates. That would help your levels from getting extrememly high. Phosphate pad is $3.29 from pets mart, and cycle is liek $6.99 for about a few months worth.