Reverse osmosis PH went ^

Just installed a hydrologic stealth 150 and my PH went from 7.8 to 9.7 and EC .5 to 0 Anyone else have this happen?


@Dave_n_St.Louis it’s because the hydrologic stealth RO150 uses green coconut activated carbon as a filter. It has a higher ph than normal activated carbon, but it is better for the environment. It also filters sediment and contaminates better so even though the ph is a bit higher the water is more pure. No conductive salts or heavy metals. The ph should level out after a bit more use as well.

All this being said, I would check the tyndall to ensure purity as well just to make sure there isn’t anything being left behind in the water.


I have the upgraded KDF carbon filter, what is tyndall? I also notice it takes less up and down to swing the PH


@Dave_n_St.Louis the Tyndall is the way light travels through water. If you put a laser pointer up to a container with your ro water in it and there is no beam going through it that means it’s as pure or almost as pure as distilled water.

If you can barely see a beam but there’s still one there that means there are some type of salts, minerals, or metals still in the water.

If you see a bright strong beam that means there’s a high ppm of salts, minerals, or metals still in the water.


@Dave_n_St.Louis ah, kdf uses electrolysis to purify. It leaves behind sodium hydroxide in the water which is extremely alkaline. A lot of water treatment plants also use it to treat acidic water and to help purify water.

So when you add electrolysis to water already treated with sodium hydroxide (if you live in a municipality that uses it) you will increase the sodium hydroxide levels creating a more alkaline solution as the water is desalinated by electrolysis.

This happens on such a small-scale though it is harmless and can easily be adjusted with a weak acid.

You won’t need to worry unless the ph starts creeping up over to 10/11 because that’s when it starts becoming harmful and corrosive.

12, 13, 14 no Bueno. Lol


Thanks for breaking it down for me. Newbie and moving from soil and air stone to filter water and setting up a Flood and Drain Table.

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