Thanks so much!
Hi Josiah, how it went the ph, you got in the range now?
I'm just now seeing your message... Yes the pH seem to be right now, about 6.5. I hopefully will get fish soon!
Thanks for checking on me,
If you have any problems later with the PH or it starts leaking you can try using a epdm pond liner with a geo textile underlayment.
I have similar problems like Josiah. I have just finished this watertank, diameter 5,2 m en 3.20 m deep.
It will be used to keep tilapia and harvesting rainwater for irrigation. My problem is the separation of the cement walls from the rainwater to not affect the ph of the rainwater.
If I were to follow the advice of Ian Cameron to paint with epoxy, what problems could arise, besides the fact that cement will not adhere to the epoxy paint?
Ian what primer should I use for the epoxy paint?
I agree with Jon Parr. Too much is being made of high pH. I've built concrete tanks and placed Koi in after a couple rinsings without any problem. Eventually the concrete will not affect the pH at all.
Jon & Bob, the irrigation water I need should be 6,5 for the tropical fruit trees I grow. I build this tank as I allready have two wells with brackish (3700 micro siemens) and high ph water which affects the trees and the clay soil (iron chlorosis).
That's why I am asking if the epoxy paint will isolate the high ph cement. The tank is to big (65 cu.m) to be rinsed.
@John - Swimming Pool Paint
Here is an update for anyone interested...
I put together a small group of pictures of my project and decided to share them here. http://homesteadaquaponics.com/pictures.php
I don't have tilapia yet but I did get some goldfish that seem to be doing good!
I'm working on finishing the grow beds as you can see and then I'll be ready for plants and fish!
Bob Campbell, I painted with swimming pool epoxy paint. The ph is 6.8 the salt level is 38.
So everything came out perfect for my fruit trees and fish. With the last rain the tank is full till it overflowed.
That's 70 cu meters= 2475 cu.ft. of clean rainwater. My only problem right now is some birds eating my fish. Thanks to all for the help.