sja said:
i have never done a 'cycle' or used filter media from another tank before
i just go by the ph .
ive never had any bad luck with this.
The pH isn't what really determines the water quality, when compared to nitrAtes, nitrItes, and ammonia.
For a tank to have finished cycling, you will have to be getting test readings of 0ppm Ammonia, 0ppm NitrIte, and less than 40ppm NitrAte.
Once your tank has cycled you have built up enough beneficial bacteria for it to be able to convert Ammonia and NitrIte [both toxic to fish] into the safer NitrAte. Until this process is completed, I would recommend asking your LFS to 'board' your fish for you until the cycle is completed, as they probably sold you the fish without informing you of the cycling process.
8 neons, 8 platies, 4 silver sharks, 3 small angels and 3 corydoras catfish.
Personally I wouldn't find anything compatible with discus except for the neons [though you risk them being eaten -- cardinals are a better choice] and possibly the cories, though they won't be as happy in the higher temperature.
Having a bioload this large in an uncycled tank isn't safe for your fish. They will be producing a LOT of waste, leading to ammonia production. Since the bacteria are not present in large enough quantities, they will not be able to convert the ammonia into nitrate.
Please take the welfare of the fish into consideration. I would recommend you read the linked topics in Sylvia's signature before even considering discus. They're not really classified as a beginner fish, and they need pristine water conditions. For someone who does not cycle their tanks and relies strictly on pH tests, I'd say that you'd need to do a LOT more research before even looking at purchasing any discus.