I have several tanks, my biggest is having some serious issues and I can't figure out why.

It is heavily planted with fast to medium growing plants, has about 2.5 watts of light per gallon, is heavily filtered and runs at a temp of 80 degrees because I have clown loaches.
Ammonia is 0
nitrites are 0
nitrates are 20
I also use homemade co2 with an electric diffuser which should help with algae as well but isn't.

All my other tanks are fine and for the most part algae free.

But my big tank is on its third cyanobacteria (blue green algae) outbreak in about 6 months.
The first time I manually removed it all and did lots of water changes.

The second time I used Red slime remover which is normally used for saltwater outbreaks of cyanobacteria but is fish and coral safe and can be used in freshwater as well.

This time it is much worse and the slime remover is doing nothing. I don't want to use antibiotics if I don't have to, but im worried this might be my only choice.
The plants are suffering and frankly I am about ready to rip them all out even though I have put tons of time and money into this tank.

Here are a couple pictures of the tank so you can see the amount of plant life, as well as my favorite little baby loaches.

http://i202.photobucket.com/albums/aa265/chadescott/Fish%20Tanks/IMG_0333-1.jpg

http://i202.photobucket.com/albums/aa265/chadescott/Fish%20Tanks/IMG_1451.jpg

I've strayed away from the hobby but used to be really into it. I got bushy nosed plecos for each tank and my maintenance went to about 20% of what is was before. But, I didn't have live plants. Plecos could be too rough for your plants. Nice tank pictures and nice clown loaches too!

Plecos will usually eat live plants and their activity on the bottom of the tank can dig them up. They also don't tend to eat blue-green algae, unfortunately.

I had that problem for awhile too. I can't remember what I did about it. It has been almost 2 years since I have been able to have a fish tank *cries* I miss them.

I believe there is something that is supposed to eat it, but I can't for the life of me remember what it is. I'll try to dig it up and let you know if I find it :-)

I don't think anything eats cyanobacteria, its not really an algae, at least not anything freshwater I think some saltwater crabs or shrimp or something do.

I do have tiny little otocinclus catfish that clean my plants and a FLying fox that does short work of any brown algae.
Snails or shrimp aren't an option either because the Loaches make short work of them. I think that might part of the problem in that tank as in my other I have trumpet snails in the substrate and a giant apple snail in each of the other tanks and they keep everything nice and clean.

I really like this article on the different kinds of algae and what to do about them. Hopefully this helps you out.

http://www.aquahobby.com/articles/e_freshwater_algae.php

Maybe try a dose of Melafix for the bacteria? It's gentle enough for use with scaleless fish. I don't dilute it and have never had any stress reactions from the loaches but some people say you need to dilute it. It's really just tea tree oil so if you already have some just figure out the dilution. Tea tree oil has many other uses around the house. I add it to shampoo to get rid of scalp irritation. Unfortunately I have no experience with heavily planted tanks so I couldn't tell you if it would mess with the C02 or delicate plants. Normally it's fine with plants.

I hadn't though of using Melafix!!

I have both that and Pimafix that I use for basic owies and when I have a fish in QT. None of the plants in that tank are delicate, the loaches would make short work of them if they were!!

I think I remember reading somewhere that Bettas don't tolerate Melafix well so I will need to probably take him out. He is a friendly guy and does fine in the large community tank.

 Quote: Jennifer Lee

I think I remember reading somewhere that Bettas don't tolerate Melafix well so I will need to probably take him out. He is a friendly guy and does fine in the large community tank.

Complete myth. Bettas are fine with Melafix. We always dosed bettas at the exact same dose as any other fish and never lost any that could have been saved.

good to know!