Sounds like the LFS
has low quality water, is your tap water clean, if so you should use an RO
filter or if you don't want to pay for one, they can be expensive, you can use tap water with Prime. You said you have a cynobacteria problem, when red slime, as its also called, dies it releases toxins into the water, I don't know what exactly. This could contribute to your other problem. You should remove all the red slime you can and use a red slime remover, I used Chemiclean red slime remover and it killed it all off within two days. Hope this helps.