Ok...so I'm having a bit of trouble with swords in my 88F discus tank. I'm sure everything else is ok. I use fertilizer and they get 15 hours of 200w light a day (in a 55g).

So...what would you recommend for a discus tank? Java ferms do Ok - hornwort seems to love the warm water - it grows exponentially every week and is a nice background cover.

What else won't cook in the upper 80's?

Gary,
the swords may do OK, but you'll need to feed them since you're kind of accelerating their growth. Echinodorus species are actually recommended on some planted discus tank sites. E. Bleheri, Tenellus, Cordifolius can handle the higher temps but typically need substantial root feeding as well as a little CO2. You can try some DIY CO2 but I'd hesitate to really recommend it with the Discus. The problem with DIY CO2 is that the CO2 keeps going into the tank, whether it's day or night. Delivering CO2 at night when the plants themselves are respirating CO2, introdces Carbonic Acid as a byproduct which acidifies the water but more than than, causes much wider swings in PH which could prove to be very detrimental to your fish. If you want to grow plants in your Discus tank, a semi-automatic or even better an automatic CO2 system is desired. Please PM me if you have more questions
regards
mike