Generally, different colors indicates different photobiologies and concurrent differences in immune responses. I'd be looking at water chemistry and shifts in microbial stuff. If you didn't do an Aquabiomics test some time ago as a benchmark I'd still suggest getting one done to help get an...
And if you want to go down a rabbit hole . . . ;)
Feldman's work at Penn State
Granular Activated Carbon Pt 1
http://www.advancedaquarist.com/2008/1/aafeature1
Granular Activated Carbon Pt 2
http://www.advancedaquarist.com/2008/2/aafeature1
Total Organic Carbon Pt 1...
Simple answer:
Do your water changes.
do not carbon dose
Keep pH 7.6 - 8.4 (7.9 to 8.3 is preffered)
Alkalinity 7-9 dKH
Calcium > 380 mg/l
PO4 .03 mg/l to .3 mg/l
Nitrate <5 mg/l
Don't bother with a skimmer or with filter socks/rollers
Do not use algae scrubbers
Keep nuisance alga to a minimum...
Fish were avoiding them. They are also actively swimming so eggs can be ruled out. Possibly larva of some kind, including snails. I suspect, since they showed up in mass at the surface within minutes of the pumps being turned off, a spawning aggregation an organism taking advantage calm...
I was doing maintenance on a system when this stuff showed up. It's a nice surprise to have something spawn or hatch out just would like to know what it is. 😕 They're pretty tiny, maybe 200 microns (1/5 mm) if I had to guess. With a magnifying lens they were really round, flattened on one...
Impressive! :D(y)
Be careful making changes too quick. It's acclimated to an old established system and maybe the worst thing to do is try to really clean it well.
For sumps and grow out tanks use whatever will fit your needs. Here's a video of one of my setups using custom refuguims along with heavy duty totes for cryptic refugiums (FYI most totes are too flimsy to safely use especially as totes get brittle as they age).
Here's a list and video of some of the "old" reef animals in one of my systems:
Purple Tang - 1995 (rehomed 4 times) (See the link to my oldest one). Yellow Tang - 2002 (rehomed 4 times. )Sinularia foliata, Green Finger, 1997 (documented sp. very rare). Green & Orange Zoas - 1996...
Don't bother. And welcome to the hobby and forum! :)
Here's some links to stuff by researchers you might enjoy:
"Coral Reefs in the Microbial Seas " This video compliments Rohwer's book of the same title. Used copies are available on line and it may be free to read on Internet Archive...
Where did you get your numbers from? Veron pointed out in his book "Corals of Australia and the Indo-Pacific" that upwelling supplied essential nutrients. This upwelling gives cprals PO4 levels up to .3 mg/l. Work done with corals at Southampton University in England with identified .03 mg/l...
Get used to it! :D I've been keeping saltwater since '87 and I'm still overwhelmed by all the information available. An if you're interested in what I think is the most important things to do to be successful, it's water changes and staying on top of basic water parameters.
All the monti's are encrusting. The juvenile colony really isn't growing that fast. However, PO4 levels are marginal which I would expect to affect growth.