I hate to join a forum and instantly ask for help on my first post, but unfortunately, it looks like I have no choice...
1. 29 gallon
3. 2+ years
4. 6 Cherry Barbs, 6 Tiger Barbs, 1 Pleco (common)
5. Yes, 8
7. Penguin Biowheel 125 Filter
8. No CO2 Unit
9. Minimal natural light
10. Yesterday, 50% to try and fix what I thought was an ammonia problem
11. I try to do water changes weekly, but have been a bit lazy lately...
12. Flake 2x daily, blood worms every other day
13. Flourescent lighting, 15-16 hours daily
14. Since I introduced the tiger barbs to the aquarium, I've had some serious problems.
a) one of my cherry barbs can no longer close its mouth and is very weak
b) half of the tiger barbs have red spots on their gills and don't swim much, lay on the gravel a lot (they were very active and swam around in a school at first, now not so much)
15. What are your water parameters?
pH is 7
Nitrate is 20-30mg/l (safe)
Nitrite is 0
Hardness is a bit high (100(GH) ppm)
Chlorine is 0
Alkalinity is 90 (KH) ppm, slightly low...
Ammonia is 0
16. What test kit are you using and is it liquid or test strips?
I'm using the Jungle 7 in one test strips
17. When was the last time you bought a fish and how did they behave while in the pet store tank?
2 days ago, the tiger barbs, and they were fine in store, active and schooled together. they also did not have the spots on the m there, although when I went back to the store today, some of their fish had developed the spots.
I've tried a major water change (50%) to combat what I thought to be an ammonia problem (though it didn't test particularly high, it is one of two causes for red gills I knew of), but that didn't do anything. I also tried aquarium salt (1tbsp per 5 gallons) because it siad it can help with nitrite damage to gills (the other cause I knew of for red gills)