Reef Tank Nuisance Algae

How much sand in a Reef Tank?

I am having a problem with nuisance algae.
I have done so many water changes it is not even funny, like 4 a week for a month now. I use RODI water.
Nothing has changed. I get the same amount of Hair and dark red algae. I have a lot of rocks and cant get to it all.
My fish store says to take out most of my sand, all of it if I can. He says I do not have enough???
Why is it not enough? If I put any more in it would look like a terrarium. LOL
I thought the live sand contained bacteria that would eat the bad stuff and keep the algae from growing.
Am I wrong? What can I do to get rid of the algae?
Thank You

You need at least 4 inches of live sand to remove Nitrate. 5 inches would be best. Any thing less is really just going to be sponge, especially if you do not have enough water movement. Less then 4 inches the sand will only contain aerobic bacteria which will convert ammonia . You need 5 inches for de nitrification.
Sand is funny in a Reef Tank, If you do not use at as a deep live sand bed then the less the better, like a dusting only. Increase your water flow with power heads and take out as much of the sand as you can. When you get things under control you can put like an inch back. Start running Phosphate removing media and cut feedings down to once or twice a week. Cut your light cycle down to 4 hours a day as well. If you have no coral then go with lights every other day and only put them on for 4 hours on your light days

Reef Aquarium Grazers