# Rapid ph change in well water



## dscobb (Dec 17, 2010)

Last week I set up a new 36 gallon fresh water tank after being away from the hobby for several years. In the past I have always had city water. I now live out in the country and my water is supplied by a well. The water coming out of my well has a ph of 6.4 and is slightly hard. I have no water softener or any kind of filtration on the well. The highest mineral I have is calcium and it is within drinking water standards.

I used pool filter sand as my substrate and after filling the tank with water and letting the tank sit for 24 hours I decided to test the ph again and was surprised when the test read 7.4. A 1.0 jump in 24 hours. I first thought it was the sand but after further research I found that to be unlikely. I now believe that the ph is changing due to degassing of the water. I have read up on this a bit in the last day however I haven't read of anyone having this much of an increase.

My main concern is how to best do water changes. I certainly don't think I should pour fresh well water in my tank with a ph 1.0 less than the tank currently is. I don't like to use chemicals. If i do adjust the ph chemically right out of the tap to a 7.0 will it still increase a full point to 8.0 after degassing?

I guess I could hold the new water in several buckets while it is degassing but surely someone has a better idea.

Any suggestions would be appreciated!


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## majerah1 (Oct 29, 2010)

What i would do,is take a bucket.Test the water daily for a week and see if once it rises to 7.4,it stays this way.If so,then just age the water for a day or two before adding to the tank.I dont like the PH up/down stuff and so i have no advice on how to use it.


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## jrman83 (Jul 9, 2010)

If your tank levels out at 7.4 and you do a 50% water change (just throwing a number out there) your ph is only going to go down to about 7.0 and then start to naturally swing back up. 

I do this all the time with adding RO water to my tanks. If the swing is mild, and personally I believe a .5 swing is fairly mild, then I don't think it is necessarily bad. When you add the water the ph will go down gradually and in the same way gradually increase back up. Nothing will be drastic and actually, it will be a natural swing Not much different than someone dosing their tank with CO2 while their light is on and then truning it off the rest of the day. The result in that case is similar in that the ph starts to lower as CO2 is added and continues to go down until it stops being added. Once the CO2 is turned off the ph starts to climb again. Also keep in mind this is a daily occurance and what your tank would be going through would only be weekly, or so.

As mentioned ph up/down products are not very good and really can only be safely added if you have 0 hardness. When you add them the swing in ph is only usually temporary (hours) as the buffers in the water fight to bring the ph back to where it was.


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## NeonShark666 (Dec 13, 2010)

It sounds like you well water is charged with CO2. Venting it to the air lets it fizz out. A high ph is very common for well water. It sits in the gound for a long time and dissolves minerals in the rocks. The one that causes the high ph is limestone and you need CO2 in the water to disolve it. I wouldn't recommend treating your water until it has had a chance to vent otherwise you will get a false reading and your treatment may be wrong. Aeriating can speed up the venting.


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