RO and tap water mix

[bzehr]

I've been using reverse osmosis water (culligan water from the local grocery store) and I have been mixing it with tap water for my 10 and 55 gallon. The water out of my tap is very hard, alkiline water. Right out of the tap it measures:
Total Hardness: 300+ ppm
Total Alkalinity: 300+ ppm
pH: 8.8
I have been mixing it at a ratio of about 80% RO, 20% tap. That brings it down to:
Total Hardness: 150 ppm
Total Alkalinity: 120 ppm
pH: 7.2
Anyway, I don't think the fish are having a problem or anything, but I have had a couple of mysterious deaths. I just happened upon an article about RO water being bad for fish because it doesn't have any minerals, electrlytes, etc. I read that it is a good idea to mix it with tap water, but I can't seem to find any information on what a good mix would be. Does anyone have any input? Am I using enough tap water in my mix? Thanks.

 

[pbrack]

I just ordered some RO right from big als online. I haven't gotten it yet, so I can't tell right now, but I can probably tell you in about a week how its working. I have the same problem, because I use an Ro/Di unit for my fish. I think your tap/Ro ratio is good, but I think you should check for heavy metals!

Hope this helps!

 

[Avenolpey]

You definitely need to reconstitute you RO water. Mixing with tap might work, but you are still putting all the bad things in your tap water into your tank. You can purchase something like RO right from Kent or mix it yourself. Here is a link to a formula.

http://www.thekrib.com/Plants/Fertilizer/dosing.html