Images, regional, and general info:
Regionally, we draw a water from a lake that has a major problem with algae; so, perhaps algae spores are coming in from the tap? I have been considering pre-filtering the water.
I am about to throw the tank away (as the top answer suggested) because I have worked on this problem for over a year and gone so far as to scald the tank and re-stock everything. Nonetheless, I am willing to put in one last great effort and pull out all the stops so please let me know if you have a solution (less extreme is better, but I thought maybe the algae spores are in the sealant so I can't even give it away because I would just be giving someone else a problem).
Lights: 6 hours (on timer) white LED lighting [I cannot find the manual, but I think it's 80 watts (could be 50, could be 100)]. There is a blue-light (night mode) setting that I never use.
Volume: Using a a 50-gallon freshwater tank.
Filters: Penguin Bio-Wheel 350 multi-stage filter; REMOVED AAUV24W burned out 3 days ago--removed it. That's the one I use on the 10-gallon tank that I use if fish need to go into isolation.
Heater: EHEIM 150watt aquarium heater.
Failed CO2 Injector: The CO2 diffuser got clogged with algae and broke a few months ago.
Thermometer: Also have a glass mercury thermometer that is not compromised.
Top: There is no air-tight seal.
- Algae grows all over my aquarium (plants, equipment, rocks, glass, you name it).
- And tons of snails!
How I treat the tank:
- I think the substrait is Ecocomplete Carib Sea (which might be too rich).
- About 12 fish are in there (one Rafael catfish, one Chinese algae eater, 2 guarami, 2 swordtails, 2 platies, 5 serpie tetras, 1 neon tetra.
- I change about 1/4th of the water every week, usually drawing water from the bottom, and 3/4ths of the tank if a fish is ever sick.
- pH ranges from 7.4 (when the water is changed) to 7.8 (when I scrub the algae off the walls).
- Rocks, toys, and gravel are scrubbed diligently and set at a rolling boil for 30 minutes prior to being added to the tank.
- New fish go into my 10-galon isolation tank, which is much cleaner, for about a week, and then adjust in a bag for a while before being added to the tank. We don't get a lot of new fish (anywhere from once per 2-3 months to once per year).
What I have tried:
- Moved all fish out, moved it to the garage, cleaned every nook and cranny multiple times with bleach, let it completely in darkness, replaced all equipment, new materials (soil, gravel, rocks, housing structures--boiled it all for 3 minutes per item, first). Failed.
- Treatments. Killed all the plants and probably some fish. Failed.
- Moved from fluorescent to LED (seemed to make it worse). Failed.
- Moved the whole tank away from sunlight (may have slowed it down, not sure). Failed.
- Have always been sure not to over-feed the fish. Failed.
- High-volume bi-weekly water replacements (3/4ths of the tank). Failed.
- Adding a very small amount of bleach to the water--the fish surprisingly did fine. Failed.
What I have not tried:
- Pre-filtering the water.
- I am legitimately at my wit's end. What should I do?!
- I have to get rid of the algae! It looks like a toilet!!! How can I make it stop!? And these darned snails, too!?