I just redid my 8gal Endlers livebearer tank. Had gotten a real hair algae problem, and just decided to start all over. Didn't have another tank to use temporarily, so I cleaned out the whole tank, even cleaned out the filter, cleaned off the driftwood, put the fish in a 5gal bucket. I put in new substrate, and brought in plants from another tank. The only plants I kept from this tank were some petite nanas, so I spent a bit of time with a magnifying glass and tweezers to make sure there was no trace of hair algae on them. Let the tank rest from afternoon till late evening, then put the fish back in, and crossed my fingers. Now it is 24 hours later, and all seems well. Probably not the best thing to do, but sometimes you don't have much choice. It would have been better to just leave the filter till later, after the tank had been running for a while, but I was afraid there might be a trace of the hair algae in the filter. And the Endlers, as with guppies, are pretty hardy. This might not work with all kinds of fish.