Acidic Reverse osmosis water

[Greenvein]

Hi guys I have a RO/Di water filter system 6stage. I have read everywhere that ro water is neutral at 7 pH but mine is coming out at 2.4ph. my ppm/ec is at 0.
My tap water is 10.5ph and 400ppm/.8ec
Any ideas what's causing this?

Thanks

 

[Peat Phreak]

It absorbs CO2 from the air. This forms carbonic acid. Since there is nothing to buffer it, the pH drops. But it should not drop that much. 5-6pH is not unusual.

Maybe there is an issue with the deionizer? I'd contact the maker of the water filter.

 

[Greenvein]

It absorbs CO2 from the air. This forms carbonic acid. Since there is nothing to buffer it, the pH drops. But it should not drop that much. 5-6pH is not unusual.

Maybe there is an issue with the deionizer? I'd contact the maker of the water filter.

Yes even after adding calmag or food it is still very low I'm currently mixing with my tap water to get a happy medium but rather use the RO..
It's in a tight spot but probably best bet to test before the DI..
The unit I bought was used but for aquatics and the seller had put all new filters in before sale.

 

[Peat Phreak]

It's in a tight spot but probably best bet to test before the DI..

Yes, that sounds like a good plan if you can bypass the DI. I've never heard of RO getting that low.

 

[Phytoplankton]

Somethings not right, a PH of 10.5 is extremely basic (about the same as milk of magnesia), a ph of 2.4 is the same as vinegar???? Might try re-calibrating your PH pen. A PH of 2.4 would kill your plants on contact.

 

[BeccaBuds]

I use a DIY recirculating water purification system that uses a column of catalytic carbon and a column of mixed bed, nuclear grade deionizing resin that produces very pure water with a resistivity of 3 to 4 MegaOhms/cm (conductivity of 0.33 to 0.25 microSiemens) and pH of 3.8-4.2. With just pure water a few drops of pH Up raises the pH to 6-7 so it hasn't been a problem for me. Even though the resin is mixed bed and removes both anions and cations, the process is more efficient with one than the other so the solution becomes acidic. pH Up will fix it.

 

[Greenvein]

Somethings not right, a PH of 10.5 is extremely basic (about the same as milk of magnesia), a ph of 2.4 is the same as vinegar???? Might try re-calibrating your PH pen. A PH of 2.4 would kill your plants on contact.

I use a DIY recirculating water purification system that uses a column of catalytic carbon and a column of mixed bed, nuclear grade deionizing resin that produces very pure water with a resistivity of 3 to 4 MegaOhms/cm (conductivity of 0.33 to 0.25 microSiemens) and pH of 3.8-4.2. With just pure water a few drops of pH Up raises the pH to 6-7 so it hasn't been a problem for me. Even though the resin is mixed bed and removes both anions and cations, the process is more efficient with one than the other so the solution becomes acidic. pH Up will fix it.

Cheers guys I'm not sure how I was testing before but I'm now reading around 6 something and 0ppm so I have started using RO again but buffering it properly and so far it seems to be great.

Cheers for the advice

 

[Phytoplankton]

That sounds right.