Water Level and Strange Algae

[Infinity]

Well... For the last month or so, I've been running into this issue.
Water level drops very quickly. I have a 50 gallon tank and water level drops like an inch a week. And the substrate and LR quickly seem to be covered with this rust colored red algae. I've been doing like 40% water changes every other week, I tested the water the PH is fine, no sign of ammonia, nitrates and nitrites. I have the Phosphate sponge in my magnum 350's canister. And my Emp 400 has Purigen and black carbon in it. All the fish seem ok, no ick nothing. I'm stumped, what's wrong? what should I do?
Also, under the LR and filters are developed this little white shell things. I was told this is normal if there is more nutrients in the water as these are some kinds of worms. I'm really stumped, the protein skimmer seems stuck as it doesn't seem to pick up any more stuff out of the water, I might need to readjust it again. Any ideas?

 

[fishfreek]

When the water falls are you replacing it with fresh water or saltwater? The amount of evaporation your talking about is acutally not much. Most of us see about 1gal of evaporation a day from a tank that size.

Since the salinity increases as the water decreases its important to try to maintan a set water level by replacing evapriated water with freshwater every day to every other day.

Have you changed the carbon?

What kind of water flow do you have aside from the canister and the Emp 400?

 

[pufferman]

Just top off the water and consider getting some turbo snails.

P-MAN