Frustrated...ammonia issue in an established tank

[TXaggie]

I thought everything in my established tank was going well, and added some new fish on Tues. I noticed my cories going to the surface a lot and tested my water, and I had 1.0 ppm ammonia!! So frustrating. I did a 50% change and dosed prime for the tank volume tonight. Here's the tank stats:

29 g, moderately planted, AC 70 w/ sponge and 2x biomedia
5 cory habrosus
3 cory pygmaeus
5 threadfin rainbowfish
4 danio choprae
2 algae goby
1 Endlers guppy
2 small mystery snails
2 nerite snails
Cherry shrimp

On tues I added:
4 danio choprae
2 Endlers guppy

Did I way overestimate what my bio filter should be able to handle? I don't normally test my water with every water change since my tank has been stable for so long. I added some fish (Danios and 2 Threadfins) about 2 months ago and had a similar issue, but I thought it was due to having recently removed Purigen from my filter (I still haven't gotten around to recharging it).

So what am I missing? I didn't think adding 6 small fish to an established tank would be too much...

So now I'm looking at 50% WCs, daily, I guess? How long can I expect it to take for my bio filter to catch up? Is there anything I should be doing besides using Prime with the WC to protect my fish?

 

[TXaggie]

What about my prefilter? Has anyone had an issue with a prefilter causing problems? Any suggestions/help is appreciated....

 

[Brookster123]

Sounds like you stressed the bio filter by adding more fish, the tank seems a bit on the heavily stocked side.. It should catch up in a weeks time though.. Keep an eye on water parameters..

 

[TXaggie]

I'm glad to hear things might be improving in a week or so, I really wasn't looking forward to a month of constant water changes....I guess if I test nightly then I can keep up with it. 50% changes with Prime to help detox sound about right? I don't want to loose any fish, but is also don't want to stall out the bio filter catching up.

 

[BBradbury]

Hello TX...

Typically, a newly set up tank should have 3 to 4 smallish fish species for every 10 gallons of water. So, on the high side you should only have a dozen until you get the hang of taking care of the water. By that, I mean setting up and following a tank management routine that includes 50 percent water changes weekly for a small tank, good vacuuming of the substrate, introducing some floating plants to help keep a stable water chemistry and servicing the filtration regularly. Once you get used to the water keeping hobby, you could add more fish.

B

 

[TXaggie]

Hi BBradbury, thanks for the advice! I should have even more clear about my tank maint. My tank has been running for about 2 years now, and I'm at the point where I'm able to manage weekly 50% WC. Sometimes I'll go every other week if my nitrates are low to allow my stem plants to get some nitrogen. I don't test my water all the time, but I do check it periodically. I don't have floating plants, but I do have bacopa and rotala to help soak up extra nitrates.

It sounds like I may have just added too many fish at once? Would you recommended adding more biomedia or changing something else with my filtration? Will purigen be helpful in water quality as well as clarity of the water? I liked the way the water looked when I was running that in my filter.