Treating cyanobacteria with Maracyn

[Bbarb27]

Hi -

I'm not sure if this thread should be here or general discussion, but since it's regarding meds, I'll post it here.

I have an outbreak of bluegreen algea/cynobacteria in 3 tanks that I am planning to treat with Maracyn since I can't seem to eradicate it any other way. It started in my 10 gal when I changed lighting and then spread to my two 6 gal betta tanks via the syphon (I think).

The 10 gallon has white cloud minnows and 2 week old fry, who are still the size of splinters of glass. Will the maracyn hurt the fry? The two betta tanks each have a betta and no other stock. Do I use full strength maracyn or 1/2 dose?

Any other insight into treating cyno would be appreciated. I have reduced feeding and changed out the problem lights and physically removed as much as I can from each tank. I've read conflicting reports on whether the erythromycin/maracyn will affect the bio filter. Each tank has HOB filter.

Thanks!

 

[Ed Stansbury]

Anything you do to your fry tank is likely to kill your fry, not from the treatment, but from the shock to the ecosystem. Once your fry are grown (or moved out), you can try regaining a better equilibrium. Killing cyanos won't change the conditions that allowed it to take over in the first place. With small daily water changes, thorough siphoning of the gravel, and adding quick growing surface plants to soak up any excess nutrients, you can re-balance. For these reasons, I've never used chemicals to treat any ecosystem problem. Hope that helps.