Too many in the clean-up crew...?

[DaveR11]

My tank is now 4 months old. It is a Red Sea S-650 and my clean-up crew consists of the following:

• 6 red-legged hermit crabs
• 4 large black footed Trochus snails (down from 6) plus hundreds of babies
• 1 Large Mexican Turbo snail
• 5 Nassarius snails (down from 6)
• 1 Peppermint shrimp
• 5 Astraea tecta snails
• Lots of Stomatella snails (at least 30 of various sizes)
• 1 Strombidae fighting conch
• 1 Large 'caramel' snail (lives in the sand)
• 5 Cerith snails

My nitrate has dropped from a peak of 25 down to 0.2 (Salifert test kit). I have never detected phosphate. I'm running a skimmer, carbon, macro algae and a bio-pellet reactor in the sump.

I've been through a number of algae phases - brown diatoms, green film, green hair, red cyano. Now all I have is a little green film on the glass which needs a clean every couple of days, some harder to shift green spot algae, the odd bit of bubble algae and various hues of coraline. My concern is my CUC are running out of food. All my fish are in the hospital tank after the Ich outbreak but in another month (hopefully) they will be back in the tank including a yellow tang. My concern is the algae eating part of the CUC are running low on food and this will get worse when the yellow tang goes back in. I'm still feeding the shrimp and LPS corals every 3 days with Mysis

My questions are:

• Is it too large a CUC for the size of tank?
• Should I supplementary feed with nori?
• If I were to downsize the CUC which to trade in? I'm looking at you Mr Mexican Turbo....

I may of course be tempting fate and there could be another algae outbreak...

 

[Oxylebius]

I think you have a good amount.

In my 65g tank, I have 6 nassarius, 4 nerites, 4 ceriths, 1 astraea (lots two in last month these are >3 yrs old), 1 fighting conch, 1 dwarf Hawaiian zebra hermit crab, 2 cleaner shrimps, 1 peppermint shrimp, and 3 scarlet reef hermits.

 

[DaveK]

What you have for a CUC is actually rather small. Some use as many as 1 snail or hermit crab per gallon of water. A few go to even higher amounts.

I wouldn't change anything unless your having a problem someplace.

 

[Blue Space]

Trust me. Crabs will sit there on the sand eating seemingly nothing -but they are eating. Remember that yellow tang you had in there? He made lots of food for everyone. When you put that yellow tang back in he's going to create a lot more food for them. Let the snails clean your glass and so don't worry about feeding the cuc.

 

[Oxylebius]

W/o fish in the tank you may want to feed an algae pellet or nori every so often. The amount you feed will depend on the amount of algae growing (or lack of). In particular that shrimp could use some food w/o fish poop in the tank to eat. And if you see your crabs going after your snail, I'd definitely get some food in there for them.

 

[DaveR11]

Thanks everyone I will leave things as they are.

I forgot I also have 2 cleaner shrimp. I'm feeding all the shrimps every three days or so, partly to keep them off my LPS corals when I target feed them. I'll add a little nori. When I was trying to catch the fish I baited the fish trap with nori and the Mexican turbo found it pretty quickly. I'll also keep an eye on the hermits.

Many thanks for the advice.