keep feeding the dt to make sure nitrate and phosphate don't fall to zero (you'll get dinos)
Yes, thanks for that I did suspect that would be the case.
Interestingly though, although I haven't tested it (and I will and report back) the DT sump has now suddenly got GHA growing in it and the DT has brown "dust" algae so not probably any chance of dinos.
I put that down to the fact that I'm feeding with a smallish amount of brineshrimp but there's only two cleaner shrimps to eat that, and if the don't get to it in time, it's going into filtration system and decomposing there, hence a probably higher phosphate/nitrate load.
What do you think?