Faded, Shy Endler

Hello all.  First time poster here!  After some advice with regards to a sorry-looking Endler in my tank.

The last couple of days he's been either hanging around on the bottom of the tank or sitting in the 0.5cm of water on top of the filter!  He doesn't appear to have any visual signs of anything wrong with him other them seeming a bit faded compared with the other Endlers in the tank.  He also hasn't shown much of an appetite in the last 48 hours.

About a week ago I lost a male guppy who seemed to endure similar symptoms.

I have a 150L Fluval tank, just over 6 months old.  Water readings today (API liquid test) were:

Ammonia 0
Nitrite 0
Nitrate 40 (my tap water is also just below 40)
pH 7.4-7.6

I know the Nitrate is a bit on the high side but I'm sure I read somewhere that this level should be ok (can't remember where I saw it though!)

I do a weekly 25% water change & gravel vac.  There are also live plants - I'd probably call it 'medium-planted'.

Other tank inhabitants:

5 x Endlers
5 x Male Guppies
3 x Salt & Pepper Corys
3 x Platys
1 x Dwarf Gourami
1 x Ruby Shark
2 x Assassin Snails
5 x Amano Shrimp

I'm at a bit of a loss as to what's wrong with the little guy, and a tad concerned that this has followed quickly after the loss of the Guppy.  The other half is convinced the entire tank is going down one by one!

Any help or advice would be most appreciated.

Do you know if your tapwater is soft or hard? Endlers do better in hard water - though having said that I have softish water and mine are thriving.
Other than that, it could just be a sickly fish. Guppies do tend to be delicate these days, they are more likely to get sick than endlers normally.
All I can suggest is keeping an eye on the others for now, and if more get sick, think about treating then.


Your nitrate isn't bad. With the exception of a few nitrate sensitive species, most fish only suffer when it's in the 100s. Since you have a tap nitrate of almost 40, you won't be able to get it lower without using RO water or having the tank planted like a jungle. Your aim should be to do enough water changes to keep it at or below your tap reading plus 20 just befroe a water change (when nitrate is at its highest)