Newbe discus question

[Geoey]

I have recently set up a 160us gal planted tank with some angel fish/tetras i have an fx6 filter and no heater the tank stays at 27-30 oC due to the climate up here.
I am on bore water for the 6 month dry season which at its worse is about ph 7-7.5 GH60ppm KH 80 ppm
For the rainy season i am on rain water which is very soft i have no problem with water quantity and supply and can do very frequent water changes all year round .
Can i keep discus provided all other factors are ok .
I am fairly experienced with fish and currently have the tank well cycled and am running at 0 no2 and 0 no3.
Should i take the plunge ? a bit scared i can get assorted discus locally for about $60 each i want at least 5 so $300 for fish is a big risk ?
Years ago I tried 1 discus in a mixed comm tank which stressed out and died as i had no idea what i was doing.

 

[Yoda1]

1 Discus as you discovered is not ideal.
They prefer to be in groups of at least 6.

I would be a bit wary of the parameter swings between the rain water and bore water.
Dscus prefer stable water over what people say is "ideal" that may be constantly fluctuating.
I would inclined to use the bore water all the time.

 

[Geoey]

If i installed a second tank for rain water that will last 12 months . and do a 1/2 mix all year round so the parameters dont change would that be ok ?

 

[Yoda1]

Is the rain water coming off your roof?
What would worry me is that there is debris accumulating in your tank, and that over time, it will start decomposing.