sea hare

[Myka]

FYI, diatoms are not red slime algae. Red slime algae is actually cyanobacteria. There are more natural ways to get rid of it (like using a couple Zeo products, or by keeping up on your husbandry better) so you can avoid chemicals. Be aware that most or all of the chemical treatments for red slime algae will also damage your population of nitrifying bacteria.