pythoff looks and sounds awesome, but it wont help with snot algae.
The snot algae will make your pH rise, and the pyth will make your pH drop.
UV needs to be running right when you start, to prevent the brown algae. Dizzles right, it wont cure it once you have it due to the fact that it is already on your roots, and the UV only kills the shit that passes through it. Be very careful with the physan. I was able to kill my brown algae with a res change, and then running the physan at 1 mL/10 gal, for just an hour.
I tried running physan for the 3 days at higher doses and it killed my roots off and made the plants look very sad.
Once you flush with physan. Add EWC tea.
4 gallons of RO water in a 5 gallon bucket. One air stone with a big air pump.
2-3 handfuls of earth worm castings or ancient forest
50mL liquid carbo load
1 scoop of ZHO
1 scoop of
Great White
5mL Root Excelurator
50mL Aquashield
Bubble for 24-48 hours; no longer. Separate with cheese cloth and put in a container. Fridge for up to 10 days.
Just use 1-2 cups per 10 gallons. That is more than plenty.
^ thats a cut and paste from various excerpts on icmag. If you want to read a very long thread on the subject search richierich's thread on brown algae over there.
I just did this, and my roots bounced back after about three days. The EWC tea is the shit (literally!). I will be using it for the rest of my grows. Its easy to make if you have enough space for a 5 gal bucket.