Puffers And Nitrite

[tommygunzz]

hi there in my tank i have
1 blue stripe puffer
1 valentini puffer
1 damsel
and some hermit crabs.
my water all tests good for nitrites and amonia right now but my fish are laying on the bottom, they dont seem ot be breathing heavy or anything.
My second problem is i keep having crazy nitrite spikes...from 0 to 1.8 in 4 - 5 days?? consistantly for 4 weeks now any ideas???
i have cut my feeding almost completly off do reqular water changes and never have any amonia??? any ideas??
Thanks everyone in advance, as i have been working closely with my lfs but they cant figure it out either

 

[SkiFletch]

Either a parasitic gill infection, or more likely inadequate water flow (especially surface water flow). Point a powerhead at the surface of the water to stir it up, sounds like your fish are suffocating from lack of Oxygen as a result of poor gas exchange at the water surface. Make it quick too, a problem like that can crash the tank in a matter of hours

 

[tommygunzz]

i went out and bought a aqua clear hang on meant for a 90 gallon tank and added that on and am running a rena xp 3 with the suface skimmer and the outlet 3 inches from the bottom of my 90 gallon tank? should i be looking at getting another power head?? The lfs told me i dont need a protein skimmer but i am buying one this weekend as i feel i should have it