Is death around the corner? :'<

Basic Info:
10-gallon tank
7 plastic plants
a couple of rocks and a lot of gravel
1 divider
1 blue male betta fish
and 2 female betta fish

Things to consider:
My room is a bit cold, and my 10 gallon tank doesn't have a heater. I tend to have the curtains pulled back, so the sunlight can hit the tank and keep it somewhat warm; I am working on getting a heater soon, though the water sometimes gets a bit cold (not ice cold), the fish are always energetic and active.

Synopsis:
(I change my tank's water every week or so, if I don't I change about 25%-50% of the water. NOTE: at ever water change I condition the water with Aqueon Water Conditioner.)
(YESTERDAY) It was time for another routine water change, the water was getting a bit green and murky and it was because of algae growth. I have been having this problem for a while and I just hate that my water gets so dirty, so fast, so I sent my father to go buy some algae control. He brought back a small bottle of Tetra Algae Control, and I began the water change. I took the fish out placed them in separate containers and cleaned everything from the gravel to the plants. I filled the tank up with some water and put the appropriate amount of water conditioner and let it set for 10 minutes. Within those ten minutes I went downstairs to kill some time. Turns out that in the time I was 'killing time' my father had put a couple of drops of Tetra Algae control. He said he had read the instructions and everything. Well, I put the fish right in, the newest female betta, Stellar was laying at the bottom of the tank (She did this as well in her own cup) and Angel (other female) swam around for a few, but after a couple of hours I started to notice that she began to either float towards the top of the tanks corners or stay at the bottom of the tank face down between some rocks. My male betta, (who has been with us for about 6 months) has recently been in a hospital tank because he had popeye and finrot and was now back in the tank; he swam around some, but after the same while, he too, began to display the same behavior. He would float at the top and stay at the bottom, (mostly) as if he were sleeping.

I waited a couple of hours to see if they were doing better and they weren't.

(TODAY)
Today I have them in small separate tanks, including the females, since from last night. I freaked out. I get the feeling my father put too much of that Tetra Algae control stuff and it is affecting my fish. Each of the tank contains fresh, brand new water, with water conditioner and none of that algae control stuff. The male fish is floating at the top of his little tank, but he isn't moving much, he moves a bit and changes position. Sometimes he is at the bottom, sometimes at the top. He appears to be sleeping most of the time and appears to be breathing slowly. This his been the same behavior since last night and during the entire night. My female fish seem to be doing the worst. they are at the bottom of their tanks, appearing to also breathe slowly. Sometimes they are on their sides, and appear to look lifeless. The male fish has eaten one pellet, the females have not eaten, (even though I dropped a pellet each into their tanks).

NOTE: I have all the tanks by the windows in the sunlight, so that the water stays at least at room temperature. My male betta has been treated with Maracyn II before he was placed in the tank again. All display the same behavior, the females more than males.


Is there something I can do to save these wonderful fish? I love them to much for them to just die. I have around $20 in my pocket right now and if there is a medicine or something I can get let me know....or is this the end for them? I don't want to do another water change and put them into the tank again, because they seem too fragile. I need HELP ASAP!