Green algae disappearing

[Jedi Knghit]

We went out of town for a 12 days and amazingly everything seemed to survive my tank sitter. My tank is a little over 4 months old and had gone through stages of diatoms, dinos, and was starting to really green up before we left. I have a small cleanup crew consisting of 1 shrimp, 1 emerald crab, 7 hermits, 5 cerith snails, and 1 trocus snail. I was worried that the algae would overwhelm the cleanup crew while we were gone and that it would be out of control by the time I managed to get more CC threw the 70+ day QT process. To my surprise, the tank was a little more green than we left. Rocks, a little on the glass and even a little on the sand

I started up the QT tank to get ready for more CC. Performed a water change, cleaned up the sump and tested the water. Over the last week, almost all of the green algae has disappeared from the rocks, sand, and glass. There is still some green film on the return nozzles, but the rest of the tank is almost spotlessly white.

All of the cleanup crew, fish, and few corals seem fine. The only possible death is am emerald crab, and I just spotted him this afternoon. I examined him and could not be sure if it was a molt or a dead crab.

The tank is a Red Sea Reefer 350 with (2) AI Hydra 26s.

I was concerned my nutrients had dropped, but all of the parameters have been pretty stable for months.

I am in the middle of testing everything, but here are the results so far
temp: 78.4
ph 8.08
ammonia: 0
nitrite: 0
nitrate: 20
phosphate: .25
(test kits are all Salifert)

So my questions are:

1. is it odd that the green algae is all but disappearing?

2. Should I be concerned? it certainly doesn't seem like my cleanup crew should have eradicated the green algae.

 

[lapin]

Rent out your tank sitter to people that have algae.