EMERGENCY with scleromystax barbatus

[This Old Spouse]

I got six of these about 3 weeks ago and housed them in my 20g cory tank. Two days ago, the first one died. I thought that since they were wild caught it could easily have been old age and/or stress of the trip catching up to it. I found another dead one today, full of eggs, with no signs of disease, unusual behavior or injuries. Since the only other tankmates are cory and otos, I'm at a loss. The only thing I can figure is that the pH is dropping too low from the level the tap water is at. I've pasted the form I think I'm supposed to use. Please help.

1. Water parameters
a) Temperature range 72-74ºF
b) pH. 5.0
c) GH. 0
d) KH 0
e)Ammonia, Nitrate, Nitrite, levels. 0/0/0
f) Water change frequency: at least once a week.
(Most LFS's will check your water and give a list of readings).

2. Tank set up
a) Size. 20g long
b) Substrate. sand
c) Filtration. Eheim Ecco and Whisper 40 HOB
d) Furnishings. Large driftwood piece, smaller driftwood piece, both with Christmas moss, several Amazon swords and a few bulbs that are just starting.
e) Other tank mates: 2 hi fin pepper; 4 peppered; 8 leukomelas; 7 trilineatus; 4 scleromystax barbatus (filigree); 2 synodontis cats; 2 oto
f) How long has it been set-up? Approximately a year

3. Symptoms / Problem description
Dead with no apparent symptoms or behavior or injury
4. Action taken (if any)
I'm taking it here.
5. Medications used (if any)
None

[medaka]

It is a bit hard to diagnose your problem exactly over the internet as you may appreciate.
However, at first glance it seems to me that you need to raise both your pH and GH. This should not have any adverse effect on the other inhabitants of your tank; actually your Syno's will benefit from any raise in PH & GH.
It may be worth adding something like a small piece of tuffa rock to stabilize both the PH and GH. I know one guy who adds marine coral sand to his substrate to buffer his water up.

Also do a check on the PH from the water source that you are using for your aquarium.
If it has a low PH to start with, you can then take action to remedy this when you carry out your water changing regime.

[minkweir]

Hi, didnt the place you bought them tell you that Barbatus are a COLD water fish not tropical?
I have mine in a seperate tank to my other fish @ 18-20 degrees celsius.Any warmer the most healthy looking fish will die.

[corybreed]

Sorry to hear about the barbatus. It sounds like you have the answer. A pH of 5 is low. Are the other corys in the tank doing well? If so, they have probably acclimated to the low pH. It is not unusual for additions to an established tank do poorly when the other fish seem to be doing fine at such a low pH. Try to gradually bring it up to 6.5 to 7.

Mark