The Puffer Forum

I have a 20L brackish Aquarium (varying salinity of SG 1.003-1.005) that previously had 2 mollies, about 2" each, a knight goby, 2 bumbleebee gobies and 2 juvenile glassfish. The aquarium is cycled and planted and I have had 0 readings on ammonia and nitrite for several months with a nitrate level between 1 and 5. Ph is a constant 8.0.

I just purchased a F8 puffer from my LFS, which was in freshwater. He seems fine, but was a bit finicky about frozen foods at first, but took snails easily and for the most part seems happy. I did get him to eat frozen bloodworms though finally.

Lately I have seen an ammonia problem, and I am not sure if it is because of the types of food I have been trying (or the amount) to get him to eat, the filtration ( I am using a biowheel 150 and a whisper 10 together which combined is 240 or 250 gph) or if my tank is overstocked now. I couldn't find anything too clear about how many or what fish you can keep successfully other than the amount of puffers that can share the same space. I had been doing 25% to 30% water changes weekly before the puffer was introduced. I have been doing 5 gallon water changes daily for the past couple of days however since I started getting ammonia traces.

Can anyone offer advice or share your experience with a housing an F8 puffer with tankmates in a smaller tank like a 20?

Was the tank empty for any time between the previous fish & the puffer? Benefitial bacteria will only live about 24 hours, without an ammonia food source.

No, I guess I shouldn't have said previously, I meant what I had (and still do have in the tank) BEFORE the F8 was introduced.

I did get the ammonia down to 0 again, and will watch the feedings, but he doesn't seem too active today (although he did eat). He isn't scouring the tank bottom in search of stuff or floating around like he usually does, or coming to the glass when I come by, he is just kind of keeping to himself in one or two spots today...often by the heater. The temp is 80F

Then the ammonia produced by the F8, has no extra bacteria to eat it. Just keep testing & do water changes accordingly. How much are you changing now & how often?

Since I got the F8 a little over a week ago I have changed water every other day at about 2.5-5 gallons each WC. The ammonia was at .5 last night so I did a 5 gal change and this morning it was still at .25 so I did another 30% WC. The tank has been set up for 4 months now and originally housed 9 mollies, the other 7 are in a 30 gallon livebearer tank now. I then added my knight goby and the 2 glassfish from a 10 gallon brackish tank that I already had running in with the 2 remaining mollies in the 20 about a week before the F8 was introduced. I added the 2 Bumblee Bees 3 days ago. Even though this seems like a lot of fish added fast, I actually took out more than I added and a few of the mollies I took out were considerably bigger than the BBGs or the glassfish...

I think it's most likely just a stocking level issue, nothing more than that a heavily stocked tank is much easier to put off balance. We recommend 15 gallons per F8 for swimming room but 10 for bioload, so I'd say everything other than the F8 and the knight goby is in the overstocking area, bioload wise.

Nick wrote:I think it's most likely just a stocking level issue, nothing more than that a heavily stocked tank is much easier to put off balance.

I decided that this is probably best too, and moved the Mollies to my 30 gallon livebearer tank and the Glassfish to another tank I had. It should make feeding the puffer and the BBG's easier now as well if not an easier diet overall. I can't really move them out so hopefully the F8, the Knight Goby and the 2 BBG's will be not perfect but an acceptable bio-load.

Thanks for the advice and information.

Good luck