Flow Rates and Small, Young Fish

[fkshiu]

Keeping the skimmer on at night and increasing surface agitation with powerheads is all you need along with removing any glass covers.

An airstone will create a lot of salt creep. Lowering SG to 1.021 will be hard on your inverts in the long run.

[Kevotron]

If it is an oxygen issue, why not just remove the tank lid all together, and use the same plastic grid to cover the top so no fish will jump out ?

[reefbyremote]

I hoped to keep the lid on in order to minimize evaporation as for now I do not have an auto top up. As a "middle ground" I am considering using the same plastic grid to replace glass feeding sections at the front of the lid. The plastic grid we used is too thin/flimsy to cover the entire top of the tank without a frame, so egg carton (or is it crate?) would be better for that purpose. Thank you for the help Kevotron.

In the meantime I have propped open the lid's front sections about 1/4 to 1/2 inch. With this and the other changes (skimmer running 24/7, refuge light on, k3 pointed at surface, temp down from 79 to 75) the fish have been active and acting normally now including eating for 1.5 days. Oxygen is clearly no longer a problem (but at least I know now very well the early and later symptoms.) I plan to monitor a few days before making further small(er) adjustments again. fkshiu I will listen to your warnings about reducing salinity and the use of a bubbler with an airstone and not make these adjustments either. Thank you.