bad water quality and wasting disease/internal parasite??

[Adastra808]

I have a 15 gallon tank that has been set up for about 6 months. The tank was fully cycled before I added any fish. I have it stocked with 3 otos, 5 white clouds, and 6 cherry barbs. I also have a large amount of java fern and a couple of medium sized crypts. I was doing 25% water changes weekly, and in the last 2 weeks have increased to 15-20% biweekly water changes, and I gravel vac every 2 weeks. I keep the temperature at about 78 F, and the light stays on for about 8 hours a day. The tank does not get any direct sunlight. I feed a small amount of tropical flake once a day and some frozen brine shrimp once or twice a week.
Any ideas as to why my nitrates are around 45 ppm? I have a huge amount of algae growth, particularly brown algae. I'm not sure where I'm going wrong.

Also in the last week, I noticed one female cherry barb, and one white cloud looking a little thin. Now they are both extremely thin with humped backs and concave bellies. Could this be due to the high nitrates? Or is it more likely some kind of internal parasite?

 

[VIPER006962948]

If your using tap water for wc it may be high in nitrates therefore feeding the algae. Test your water source that your using for wc.

Sent from my R800x using MonsterAquariaNetwork App

 

[duanes]

Those nitrate are high, and it is known that high nitrates contribute to columnaris out breaks at temps in the 80s. Although your temp of 78 should avoid that, but, white clouds don't do well in temps above 72'F, and if stressed they would be prone to other maladies, that might effect the other fish.

 

[Adastra808]

If your using tap water for wc it may be high in nitrates therefore feeding the algae. Test your water source that your using for wc.

Sent from my R800x using MonsterAquariaNetwork App

Do'h didn't even think of that lol. But my tap water is showing less than 10 ppm so that shouldn't be causing a problem. I did a 50% water change a couple of days ago, and re-tested today and it was down to about 20 ppm. Also started another round of medication for internal parasites and bumped the temp down a few degrees. Hopefully things will start to balance out soon.