Algae again?

So I seem to be having algae taking over my betta tanks again.  Indy's tank has something that looks like brown beard algae and Sumo's tank looks to have 2 or three different kinds of algae in it.  Not only that, but the food blocks that I left in there when I left for 10 days disintegrated all over the sand and neither the bettas nor the snails have disposed of it.  Last time I use that brand I guess.  I think it's getting bad enough that I need to do a complete cleaning so this is what I'm doing:

Step 1: transfer Sumo the betta to quarantine tank, put 5 ghost shrimp in Sumo's tank, change filter cartridge, and leave lights off for a while

Step 2: remove filter for 6-8 hrs, add Tetra Algae Control to tank, wait for algae to die

Step 3: remove decorations and lucky bamboo, clean off

Step 4: clean filter thoroughly; replace filter cartridge

Step 5: change 25-50% of water, carefully removing whatever remaining food waste the ghost shrimp haven't taken care of, dose with bacteria supplement

Step 6: remove most ghost shrimp, leave 1 to see if Sumo will coexist with it, transfer Sumo back to tank, repeat with Indy's tank

I'm not sure why I'm getting algae problems, but it's entirely possible I'm not changing the water frequently enough.  I used to change it more often but was afraid I was overdoing it so I probably went to the other extreme.  I guess it's time to start a chart again.

I'm considering downsizing once I get the tanks back in good order.  I think it would be much less hassle if I could just concentrate on the 36 gallon tank and one betta tank.  The glowfish and tetra tank is cool, but it's really getting to be a hassle maintaining 4 tanks.