Algae grrrrrrrr

Ok I have three tanks in the house that are doing this. All are betta tanks and they are in three seperate areas. The ones I am going to show you are in the living room. But the other two that do it aren't. One is in my fishroom and the other is one of the closet bettas. All my bettas eat the same foods and what you are seeing in this picture is one days growth. Does anyone have any ideas as to why these three tanks are growing algae while the ones surrounding them are clear?

This is Cage's tank, you can see Levi in the background ans his tank is clear.

Ok, this is Nova who is on the other side of Cage, his is crystal clear. This algae is really thick and sticky. It concentratres on the top of the water, sides of the tank and the gravel. I have to go in after it by hand and it peels off in sheets.

Sorry ) I just think Nova looked pretty in that picture

that's kinda gross i'm definately no expert at algae, but do you think maybe it's something in his rocks? little algae seeds or something... wow i really have no idea what i'm talking about, but maybe if you put some fresh rocks in there, or give those ones a really really really good scrub?

That's what I was thinking, something with the rocks. They do look a little big, and it may be hard to get a good cleaning on them with a vacuum. I would change them for smaller rocks, that way you can churn them up when you vacuum, and so nothing can spread like that. Also, they aren't near sun I presume?

I did consider the rocks, however, all four tanks out there have the same rocks, only one has a problem. The tank in the closet also has gravel, but smaller grain, and the one in the fishroom is a bare tank. I think it has something to do with the fish. Purely because the one in the closet, I switched tanks on him and the old tank stopped the growth and the new tank started...

algae are for the most part microscopic organisms that would be in all tanks and in most water you only ever see them or the become a problem when they over populate. algae reproduces asexually basically by splitting themselves in two or budding off, so forth and so forth, (there are a fair few ways for different species)
now they are overpopulating for a reason and it would come down to, nutrients and light.

if there are lots nutrients in the water they grow more and the same goes for light. the actual algae will always be there so my suggestion is to do a 2 large water changes over the next few days to help remove nutes, move it to a place of less light and feed him less for a while.

i dont know if you could add anything but thats my best guess of what to do.

see ya mate

I just don't understand why it would happen to three tanks out of my 8 billion. I do water changes daily on those three tanks, and I remove the algae every night. I worry about them as they are air breathers, and the algae gets so thick on the surface. I really think that my betta Thor (who is in one of the three likes it. The other day I honestly couldn't find him and turns out he had made himself a cave in it and was hiding

i wouldnt have a clue why it would hapen to just 3 mabee the species of algae in those 3 suit the conditions and are not found in the other 8 billion, it certianally is odd and as beatas not only breath air they also breath water and algae can lower the 02 levels in the tanks, it could also be bad. its wierd .

If it were me I would move each fish and sterilize each tank with bleach and start over. Since they are "air breathers" you wouldn't want anything interfering with that. I tend to take somewhat drastic measures in these type of cases. Never had that happen though.