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I was just wondering if it's considered safe for aquaruim fish to use pure rain water in a tank. What there be any advantages or disadvantages in doing so?

If you live in a non-industrial area where rain water passes through a relatively clean atmosphere, then rain water, once filtered, should be fine for soft water-loving species.

In the same breath I can't guarantee that acid rain won't be a problem.

--garyroland.

Last edited by garyroland at 14-Jan-2005 21:08

i'd like to add a few more things to gary's reply
i think that rain water has relative low and unstable pH
as water passes through the atmosphere it reacts with CO2 and lowers the pH
as the conc. of CO2 varies, you will have a slightly different pH everytime

Rain water is great but not by itself. In general you should consider it to be very "soft". That is GH and KH will be very low. In general, fish will have a difficult time in pure rainwater as it does not contain the basic salts and minerals for them to sustain themselves and grow.

However, rain water is a great medium to "soften" your water by establishing a mix of rain water and tap water. Say that your tap GH is 8 gdh and you would like to push it to 2 gdh. Rain water will approach 0 gdh. Given those assumptions a mixture of 3:1 rain to tap water will reduce your gdh to 2gdh.

Problems with rainwater are: collection without contamination, storage and reliable supply.

Last edited by Bob Wesolowski at 15-Jan-2005 19:56

__________
"To steal ideas from one person is plagiarism; to steal from many is research."
researched from Steven Wright

I have used some rain water before but since of the unstable ph you must add at least some regular (conditioned) water and it was fine. One of the troubles though is getting to it before anything else can spoil it.



==fish1[hr width='90%'][hr width='40%'][hr width='20%']

Thanks for the replies. I thought that possibly the ph and the fact that rain water doesn't contain any minerals might pose a problem. I'll just continue to use the old reliable dechlorinated tap water.

Hi,
I only use rain water because that is all i have access to. So far it has been fine, and while it is very soft and my water is quite acidic (below 6) my fish are growing well and are very colourful (but i have mostly amazon fish). Oh yeah - and i add some salt every now and then. Hope this helps!

Hiya,

i am certainly no expert, but I live on tank water gathered from the roof of my house and I had nothing but trouble. i got advice from a long time LFS expert I knew in another town and she said that fish wouldn't thrive in the water and to add water conditioner each change.

I did this and still had trouble. Eventually I discovered that lime will knock fish out. Lime is found in cement and my tank is ...you guessed it.... *cement*!!! I now have a large bucket with a lid and I bring 20 litres of water back every time I visit my parents who are on town water supply.

..I am STILL having troubles, but they are of a different kind now, changing the water source did help. It may be all misleading, but I thought I would offer some more feedback for your perusal and perhaps to add to the bank of knowledge you already have...

Ali