Questions about cleaning tank and removing undergound filter

[seagoinya]

Tank demographics:
30 gals
UGF
Whisper bio wheel filter
2 fancy tail goldfish
ammonia 0
nitrites 0
nitrate level a problem it increase rapidly so I change h20 2 x's a week 5 gallons at a time
gravel bottom
H20 temp 78 with heater

I had 2 Siamese alge eater but removed them a few months ago tbecause they were attacking my gold fish.

Just recenty the tank is growing brown alge it looks bad!
One gold fish has a sore on the base of its tailfin and is gasping. I think this is because of the high levels of nitrate. I also think the gravel is to blame for harbering too many bactria and would like to totally remove it and depend on the bio wheel for the bacteria.

I want to clean the tank this weekend and totally remove the UGF and gravel and not replace it. What are your thoughts about just using the Bio wheel? Should I replace the same water after cleaning the tank or should I start out with all new?


What type of fish can I add to the tank that will help with alge? Can I add a catfish to help keep the tank clean?

Last year the tank developed ICH I used the 1 tsp un-ionized tablesalt per gallon of h20 every 12 hours X 3 for the cure and it worked amazingly!!

 

[loganj]

Keep the bio wheel wet or all the bacteria will die off. Keep some of the water from the old setup...maybe 8-10 gallons. Replace the gravel if you wish or just wash the old gravel and reuse it. Goldfish like to dig around in the gravel. Which bio wheel filter do you have? It will either be a Penguin or an Emperor...model # please? You could add a small pleco or maybe one of the ancistrus cats to help with the algae. Snails will help with it also. Give the tank time to settle and you can do a water change if the nitrate levels aren't where they need to be.