clean up crew question

[Danno]

Still new to all this....my 90G tank has been up for about 3-4 months now and I'm starting to see algae slowly cover my rock. When it comes to a clean up crew, I've read that a good % is one snail for every gallon and one crab for every 4 gallons? Does that sound about right? If that's the case, I'm still about 40 snails short. Can they be added all at once?

Also, I'd like to add some fish that will help tackle the algae. I know that tangs are good at this, but are also territorial, so I'll add them last. I only have 4 fish at the moment and promised my wife that she can pick out a fish this weekend, so are there any colorful fish that would also help out with the algae that I could point her to?

Thanks!

 

[MofoCorals]

Their are alot of colorful tangs, foxface, I have a lawnmower blenny.
What kind of algae are you getting? You might be over feeding. How much water movement do you have?

 

[Behrmon]

I would also search for the source of the algae 1st, and also would ask what kind of algae are you seeing?

Flow?
Lighting? / How old are the bulbs?
RO?
Sump?
What fish do you have now?
Skimmer?

 

[Danno]

I would also search for the source of the algae 1st, and also would ask what kind of algae are you seeing?

Flow?
Lighting? / How old are the bulbs?
RO?
Sump?
What fish do you have now?
Skimmer?

The algae I'm seeing now is very fine and it's turning my rock slightly brown. It's not overwhelming but I want to keep it in check. I have two Hydor #3 for flow along with my return. I'll have to check that sticky about flow...I haven't read it yet.
I have 2 14K M.H. lights that are only 3 months old. I have them on 12 hour cycles. I get my rodi water from my LFS, and I do a 10g change weekly. I have a 30G sump with an octopus skimmer

I currently have 2 maroon clowns along with 2 firefish along with about 45 snails and 20 hermit crabs.

Are you saying that there should NEVER be any signs of algae?

Like I said earlier, I'd like to add some fish that help keep the tank clean, but I don't want to add any tangs yet. I only have 4 fish and I'd like to add a few more before any tangs.

I test my water faithfully. I've never had any amonia/nitrites/nitrates above normal. I've added an alk buffer just once and calc is normal.

Maybe I'll try to post a pic? Or is there a link that shows different types of algae for an ID?

Thanks for any input!