Algae Growth While Acclimating Coral

[isufishtank]

Hello! I'm new to reefing and have had my first tank, a 20 long, for about 4-5 months now. I had algae and dino problems after approximately one month, as you'd expect, and then they quickly went away. I just began the acclimation of a few SPS frags (Seriatopora, Monitpora, and one Acropora) but my algae problem has suddenly returned. I've got 4 Astrea snails that help clean up the rockwork but the algae is growing faster than they can eat and I am starting to see some bubble and hair algae that they seem to avoid. Obviously I cannot mess with lighting in the tank to combat the algae as I am acclimating coral. Another curiosity is why the algae is growing so quickly. My params are:
Calcium: 480ppm
Phosphate: 0ppm
NO3: 0ppm
Alk: 8
pH: 8.2
Ammonia: small amount detected
NO2: 0ppm

I'm unsure as to why I have any ammonia as the tank is fully cycled and I have not seen it elevated at all since the cycle. I run a small but effective fuge, biomedia, and purigen. Any advice on whats up with my Ammonia, why the algae is growing so quickly, and what to do to combat it?

 

[Bleigh]

New to salt water, so bare with me if I give the wrong advice.
Is your CUC only the 4 snails? I feel like you may want to add some variety. They may not like the kind of algae you're having issues with.

Also, I think you want a little nitrate and phosphate too - less than 5 ppm, but not totally at 0.

Algae tends to really proliferate in ammonia. What is your ammonia up to? If you do not know what could have cuased an increase in the ammonia (dead fish, too much food, etc.), it may be a mini-cycle. Who knows what starts those. Had you recently cleaned it? Maybe you got rid of a little too much bacteria?

 

[isufishtank]

New to salt water, so bare with me if I give the wrong advice.
Is your CUC only the 4 snails? I feel like you may want to add some variety. They may not like the kind of algae you're having issues with.

Also, I think you want a little nitrate and phosphate too - less than 5 ppm, but not totally at 0.

Algae tends to really proliferate in ammonia. What is your ammonia up to? If you do not know what could have cuased an increase in the ammonia (dead fish, too much food, etc.), it may be a mini-cycle. Who knows what starts those. Had you recently cleaned it? Maybe you got rid of a little too much bacteria?

I added some extra bacteria the second I noticed the ammonia was up. It was only up to 0.25 and is now lower, between 0 and 0.25, but not quite zero. No dead fish and no new livestock besides the coral. Honestly I've struggled to keep my nitrates and phosphates up, however my phosphate test is not very accurate so there might be some phosphate in there. As far as CUC goes I've got 4 astrea snails, 2 nassarius snails, 2 hermit crabs, and a CBS (not exactly clean up crew but he grabs food the fish miss). Do I need to add some more?

 

[Bleigh]

I added some extra bacteria the second I noticed the ammonia was up. It was only up to 0.25 and is now lower, between 0 and 0.25, but not quite zero. No dead fish and no new livestock besides the coral. Honestly I've struggled to keep my nitrates and phosphates up, however my phosphate test is not very accurate so there might be some phosphate in there. As far as CUC goes I've got 4 astrea snails, 2 nassarius snails, 2 hermit crabs, and a CBS (not exactly clean up crew but he grabs food the fish miss). Do I need to add some more?

I’ve read that you want at least one critter per gallon of water in your cuc. That may not be accurate though. I know that people talk about random mini cycles. I do not know what can cause them, but I’m sure someone else had more insight on them.