Not sure which Red Slime Remover you are referring to, but just be aware that the Ultralife brand (and just about any other that works reliably), is going to be an antibiotic. More specifically, it's erythromycin. Even more specifically, it's erythromycin phosphate. As it breaks down, you are essentially adding phosphates to the system. Bandaid at best.
As everyone said, you have to find the issue or it will never be gone for good. Unfortunately, if you have a really bad breakout, it is sometimes necessary to dose to save the livestock. If so, here's a good method:
- turn off skimmer and remove carbon
- half dose based on label instructions
- if no change in cyano, add the other half dose
- 48 hours later, 25% water change
- turn skimmer back on and add carbon
- 48 hours later, 25% water change
- 48 hours later, 25% water change
- 48 hours later, 25% water change
etc.
Goal is to get as much antibiotic and residual phosphate out of the system as possible. Get a good phosphate test kit (salifert) and once your levels are off the chart, you can ease up on the water changes.
Just my .02 cents...