# Anyone else have tap water with high pH/low kH?



## inspiritid (Nov 10, 2010)

My tap water has a very high pH (8.8+), and a very low kH (2), so is poorly buffered. If I draw water and leave it sit in a bucket for a week, the pH drops to 8.0. If I put that water in a tank with fish, the pH drops to 7.2. If I add CO2, the pH drops to 6.6. 

So here's my quandry: How do I do a partial water change on a pH 6.6 tank with pH 8.0 water?? Even a 25% water change causes the pH to jump temporarily. I worry that these pH swings may be hard on my fish. (I invariably see someone flicking after a water change.) (Btw, just for the record, gH is 10.)

Does anyone else have water like this, and any experiences/advice to share...?


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## jrman83 (Jul 9, 2010)

You can add a buffer to your water. How big is your tank? Partial water changes shouldn't affect it too much or not to the point of killing your fish. 

Have you tested the ph after a water change to see how much it affects it?

I have a high ph of 8.2, but my KH is 9 (well water).


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## inspiritid (Nov 10, 2010)

I bought various buffers and pHdown, and did tons of tests with them (in jugs & buckets). I found the results to be unpredictable at best -- sometimes wildly so. Enough that I'm now afraid to use them in tanks with fish.

My tanks are 5 gal, 10 gal & 29 gal. (As usual, the bigger, the more stable.) With my extremely low kH water, partial water changes *do* affect the pH -- sometimes quite a lot. 

The way I became aware of the problem was that a 50% water change *did* kill several of my fish -- the pH jumped from 6.0 to 8.0.  (When I lived in PA and had a well, I did 50% or more water changes all the time, with no problems. I suspect that like you, my well water must have been well buffered.) 

So I cut back to 25% water changes weekly -- but even then, the pH can jump as much as .6 for a little while before settling back down. I should probably go to 10% water changes twice a week, but my laziness gets cranky even thinking about that.....


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## jrman83 (Jul 9, 2010)

A .6 swing shouldn't affect your fish. Ph up or down is useless and dangerous.


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## inspiritid (Nov 10, 2010)

Yes, I threw the pHdown away! That's some scary stuff! ;D

I've been told to forget about the pH swings (while maintaining good fishkeeping practices, of course). My LFS does 90% water changes, and he swears it's not a problem. But losing a couple fish that one time has made me paranoid......

Thanks for your replies, Ben.


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## inspiritid (Nov 10, 2010)

I was still hoping to hear from someone with water like mine: pH=8.8+, kH=2. Nobody out there.....?


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