water hardness and pH problems

[Apistomaster]

I think a RO unit that produces more than ~50 gpd is excessive for a hobbyist breeding soft water fish. You should have 1-2 55 gal plastic barrels to store your RO water. That should take care of quite a few tanks.
I have been able to get by with a 60 gpd for 3 years but I am now at the point where I need a 200 gpd RO unit. I am trying to breed wild Discus again so the water changes have become larger. I have successfully bred wild Blue/Brown Discus in water with a pH of 7.4 and 450 ppm. S. haraldi is the most adaptable of the 3 Discus species. Green Discus will not breed successfully unless given soft acid water and Heckels make news when they are bred at all.

The Aquarium Pharmaceuticals Tap Water Purifier, mixed bed ion exchange resin units are the most expensive method for producing demineralized water there is. Only good for small projects. I estimate one would produce little more than 200 gal of demineralized water before the resins are exhausted when used with your tap water. You would be better off using the money towards a RO unit Your water is not that bad to begin with. The RO membrane should last you many years.
I have produced 1000's of gallons from my original RO membrane using tap water with a TDS of 340 ppm. Even without using the post DI resin filter stage my RO product water is testing at >10 ppm TDS. Soft enough for any fish I know of.
There are many Apistogramma spp that will spawn successfully in your tap water. A. cacatuoides, A. borelli and A. trifasciata will all do well enough in your tap water. I recommend you work with these before rushing into fooling around with your water chemistry. Keep on top of your water changes to keep the nitrates >20 ppm.

 

[Evan]

I think a RO unit that produces more than ~50 gpd is excessive for a hobbyist breeding soft water fish. You should have 1-2 55 gal plastic barrels to store your RO water. That should take care of quite a few tanks.

I think it depends on the window of time you have to do water changes and how much water you change. I have a setup similar to the one you describe, a R/O system that fills two 55g drums. I change about 175g of water week. But because I work, I like to do it all on the weekend. While I could do this many water changes with a 50 gpd system. I would have to do them a few days apart. So for me, 150 GPD is the least I was comfortable with.

There are many Apistogramma spp that will spawn successfully in your tap water. A. cacatuoides, A. borelli and A. trifasciata will all do well enough in your tap water. I recommend you work with these before rushing into fooling around with your water chemistry. Keep on top of your water changes to keep the nitrates >20 ppm.

I would also like to say that this is good advice. It will be much easier for you if you work with what you have. I think if I had started out by trying to learn to keep fish while striving for some perfect water chemistry I would not have stayed in the hobby long.