Red inflamed gills and sunken belly.

I have three bn. One lf albino male, one lf brown female, and one reg calico male. I had another male albino who died of unkown reasons. After that I noticed the female's belly was very sunken. I Try to feed them as much as they will eat 24 7 , cucumber, wafers, zuccini, bloodworms, fish flakes. I thought she was a goner but she keeps looking better then worse again. Sometimes I have to leave my house for a day or two so I will feed a few wafers and fish food maybe a blood worm cube thinking they will be fine for 48 hours. I have a planted tank and I leave the window open and the lights off so the plants still get some light.

Besides her sunken belly her long fins have gone from perfect to very frayed and now her gills look red and inflammed. Her belly isn't too bad right now but her gills are for sure and the male albino seemed to have red gills lately but I didn't know if it was normal because he's albino. Also I have guppies and I have had a history of problems with them, saved only a batch of babies that seemed to be growing up healthy and they too have crazy red gills right now. I have had camalanus in the past and have started my tank completely over. I have also treated tank with levamisole since i noticed her belly (but just one treatment). But I'm not sure if they all have crazy gill flukes or what. I just came home today to a dead blue gourami (female). I also have a male gourami and male and female paradise fish. I can't till if their gills are inflamed but all the young guppies and one adult female guppy along with lf bn's have red gills. The calico bn is new and seems to be in fine health. My specs always check out at 0 every time unless there is some kind of medication being dosed. I know I have a lot of white worms in my gravel but after research I believed it to be normal and also an aid to the cycle. I have tons of wood in my tank but my ph still stays at about 7.6. The lights have been off for 2 days (with just sunlight) so I will check right now to see if that is disturbing the chemistry and post an update on stats. Also I will try to post pics.

Please Help!! I google and google and google and nothing I do seems to give me healthy fish and I love my bn dearly.

Red gills usually indicate chemical burn. If! your test kit is good, and ammonia, NO2-, NO3- =0 (rarely NO3- show 0), there are chloramine and chlorine, PO4 etc.
You haven't mentioned water changes, do you use aged tap water? Any neutralizers? Do you inject CO2? Salt?
Your best shot is to take the samples of your tank and tap water to LFS and get it tested.

I checked ammonia, nitrate and nitrite. All 0. pH 7.4 I did just move a week ago so whole tank was fresh water. I use tetra aquasafe dechlorinator. I have a 50 gallon and I put a few tablespoons of salt to see if it would help the problem at all. My test kits aren't that old and there has been times when they showed not 0 so i don't think they are broke. I think I always have 0 NO3 because there are so many plants. I thought maybe it could be gill flukes but besides the red gills I still have a guppy whose wasting away and a pleco who I can't keep fat even though she eats non stop on algae wafers and veggies. Now my blue gourami has his eye popping out. It seems like there are 7 things wrong here. I have 4 airstones and lots of water circulation. 3 filters to keep up biological filtration (HOB for 30g, underwater for 10g, and canister filter for 100g) could it be an issue that i haven't changed the canister filter in a while?

its ammonia burn and/or cholrine burn. Regardless of what your test kits say.

completely refilling a tank with freshwater will do two things. First, unless you added and premixed the decholirinator then the chlorine would have had a good amount of time to burn the gills before it was nutralised.

However, once the chlorine was gone then you have the issue of the tank going through a new cycle as the freshwater kills off most of your good bacteria who process the nasty chemicals for you. Ammonia is truely a fish keepers nightmare as it is clear, odourless and kills fish. I would be heading to the fish shop anf getting some bio booster or something to boost the bacteria in your tank, add heaps of air to the water (Bubbles bubbles and more bubbles) and small water changes daily (10-15%) for a week to help get the ammonia level down.

Unfortuantly, this is about all you can do. You need to keep some ammonia in there to allow the good bacteira to build up and you also need too keep it down as it will kill the fish. the more you muck around with it, the longer the issue will persist. Horrible double edged sword. add bio booster, small water changes and patience with crossed fingers!

Agree with Doug.
You can also try Voogle. Maybe it'll help, maybe not. It won't do any harm, that's sure.
http://www.easylife.nl/en/freshwater/voogle