Need Help With My Hot Tank

[drtmima]

Hi I'd really appreciate some help. I have a 600L 2cnd hand tank setup for about 1 month now. I need some advice in dealing with water temp & co2 setup.
What's in my tank: plants - java fern, vallisneria, crypt, amazon swords. fish- livebearers, tetras, 1 pleco, total 28 fish.
substrate - amano with gravel on top
lighting: 1 unit - doesn't say wattage but has 1 blue fluorescent & 1 white fluorescent with reflectors, other unit is very bright 2x50W T8 with bright reflectors
co2: I think I have everything that I need but haven't yet attached it
water quality: ammonia/nitrites 0 tested 2x week since I got it, pH 7.8 kH 8 gH14 , 30% water change weekly
The problems: 1. The tank is very hot. This seems to be causing stress to my fish, the tetras have become aggressive & are tail nipping & I have a few wounded fish from this & some deaths. The tank is hot because it is very hot where I live, 85F at night 100F during day, the tank fluctuates 84-88 or even higher when the lights are on. So I have the lights off & I add ice as recommended in the tropical section of the forum, I keep the a/c on as much as possible but it's off during the day when we are not home, now my temp is 80-82. But how am I supposed to have a successful co2 setup with no lights??? Which is why I haven't attached the co2 yet. My plants don't seem too happy, the swords/crypts/java are ok, vallis not too good.
2. I want to treat with antibiotics for my poor tail-shredded guppies/neon- will this affect the plants? are there specific things to avoid that will affect the plants?
3. pH & gH/kH seem high - what do I do about this?
4. I have read lots about how to set up the co2 but still feel like I need more specific guidance - will posting pictures of my equipment help you advise me?
I really want to have a successful planted tank but things are not quite going that way currently... please please help.
Thanks

 

[ZoddyZod]

The problems: 1. The tank is very hot.
if the area you live in is naturally hot, there is little you can do about this other than runing you AC 24/7 or by buying an expensive aquarium chiller (sometimes used on marine tanks). Using ice seems an impractical long term solution.

3. pH & gH/kH seem high - what do I do about this?
What are the readings for each? If your tap water is high then you could either buy some RO water from your local fish shop (if they sell it) or buy yourself an RO unit to produce water with a neutral pH. However, it would need to be very high for your fish not to be able to cope with it, so would be good to know what the actual numbers are and what test kit you are using.

as for the questions on plant specifics, then hopefully someone with more knowledge will be along to help....

 

[Ps3Steveo]

If I were you I'd find a way of only using one lighting unit so it's low light, if you do this then the temp will be lower, you won't need CO2 and tbh your plants you have don't need the added light and CO2 they're all low light plants.

 

[drtmima]

Do I need to add ferts if I go low light?
And how will this affect pH & hardness?
Thanks

 

[Ps3Steveo]

PH and hardness wont change if you go low tech, use RO water, you wont need ferts for those plants as long as you have a good stock, not overstocked tho.