RO Water

[ausie fish]

Ok I now have my first fish in my 2 x 250ltr tanks (bridged) and of course I have done the normal cycle (well a bit more than normal about 10 weeks). I have 35kg of live rock in each tank and 15kg in sump (sump is a 150ltr tank) and I also have a 120mm DSB.

I think that explains the tank so far, but my question is this. I have been buying RO water to keep my SG down but it is a little expensive $5/20ltr and over the past 2 weeks I have brought 100ltrs, you do the math.

I was wondering if I could use Filtered water from those jugs, the ones that you pour water into the top and it comes out the bottom dechlorinated and most of the heavy metals are out of it. Well that is my first question.

My second one is if the above will not work can I use rain water instead, I have 1500ltrs that I collect for use in my garden, so can I use this instead of RO water.

Any advice or comments are greatly appreciated

David

[DgenR8]

I don't know what kind of contaminants rain water will pick up on the way down, or how you collect and store it. There are many potential problems.
To be safe, I recommend an RO/DI unit. It will pay for itself in no time, and save your back from those trips to lug water back to your tank.
See the good folks at www.AquaticReefSystems.com They will not steer you wrong.