RO water PH above 8.0 WTF?

I just bought an stealth RO 100 from my hydro store. I've been running it for over 2 hours 20+ gallons and the PH is still above 8.0

Has anyone had any trouble like this?

RO filters take out the dissolved solids in your water
I don't think they are supposed to effect the pH
I could be wrong though

they do effect the ph. as they remove the minerals that raise the ph levels. if the tds reading is under 10, the ph levels should be at 7.0

have you tested the TDS readings in the filtered water?

what kind of test kit / meter are you using to test the ph? and how old is it?

did you install the cartridges in the appropriate order (10micron, 5micron, 1 micron)? and what is the tds measurement after the pre-filters but before the RO unit?

what water line is hooked up to the unit? are you running hot or warm water into the RO unit?

Is there a DI cartridge on the unit?

If you got 20 gallons in 2 hrs something is wrong. There is a cartridge not in place or something. it should produce at best 4 gallons in that time.

I ran it all night long. It's giving me a reading of 7.0-7.1 now. TDS is 10-15. I was about to be really pissed if it didn't work.

I have it hooked up to the cold water connect for my washer. Should I be using the hot water instead?

Thanks fellas +rep to you guys.

Sounds like it just needed to flush stuff out and is fine now. No don't put it on how water or you will pay bigtime. Those units run off several gallons for every gallon you get.

sounds like its running fine now.
and no, you want it to be hooked up to the cold line,. hot water will have a lot more tds in it. sounds like it flushed out and you're in business now

Wellll....not exactly. The PH is fluctuating between 7.0 and 7.3 I called my hydro shop and the girl there told me that The PH shouldnt be changing at all, if the tap comes out at 7.5, then so will the RO'd water...at 7.5

She said the only thing that the system does, is lower PPM, which is coming out 15 PPM.

Then again this is the same girl that gave me horrible advice once, trying to make a sale.

Does RO water normally make PH fluctuate?

Yes ro water should have an altered PH. It should be about 7.0 on the nose. Try taking back the filters and get new ones.

To begin with there is no accuracy behind checking the pH of RO water witha pH meter. A pH meter basically is test ]ing the ratio of H+ to OH-. There are very, very few measurable H+ or OH- in RO water for the pH mmeter to use to calculate a reading. The water is just to pure.

Secondly the efficiency of a RO membrane actually increases when using hot water. RO membranes can easily handle water up to around 180 degrees F. In cold climates it is quite common to use a mix of hot and cold water for supply a RO filter. It will not shorten their life span. As for hot water containing more TDS that is absurd. Heating water does not increase the TDS but usually decreseses the TDS. It will often increase y the amount of particulates though. Particulates are removed by the prefilters not the RO membrane. The reason that you are suppose to occasionally drain sediment (particulates) from the bottom of a haot water tank is because heating the water removes calcium from the water by making the dissolved calcium into calcium particulates (calcium carbonate).

In short don't rely on pH readings of RO water.

If you can't rely on a meter to pH ro water, how can this be explained. I test my ro water to be at 7.0. I then test 7.01 calibration solution and it reads 7.0 as well. If my meter just happens to read my ro water at 7.0, and I know it is calibrated, and it reads 7.0 all the time, that seems reliable. If my meter were reading the same ro water at 6.2 one time and 8.1 the next, I would call that unreliable, but I've never seen that. I don't have any answer to this, just wondering.

So I won't be able to get an accurate PH reading of my RO unless it has nutrients in it? It makes sense to me that the water is simply to pure, and therefore not have anything to take a measurement of. I took a gallon of RO water and added maybe 1/100 a drop of PH down (a tiny bit) and the PH dropped to 5.0...but then began to fluctuate between 4.8 and 5.1

If I were to make 6 gallons of RO water for a new grow (without nutrients) how would I go about buffering pure RO at 5.5? Or is that asking to much? I may add a drop of superthrive to each gallon...so I guess not exactly pure.

I had PH issues in the beginning of my last DWC/Bubbleponic grow, and I'd like it to go as smooth as possible this round.

Illegal I agree. I didn't pay 200 bucks for an RO system to get fluctuating PH. The distilled that I had been using always read 7.0

I bought new batteries and re-calibrated my meter, and still fluctuating.

fatman7574 said:

Secondly the efficiency of a RO membrane actually increases when using hot water. RO membranes can easily handle water up to around 180 degrees F. In cold climates it is quite common to use a mix of hot and cold water for supply a RO filter. It will not shorten their life span. As for hot water containing more TDS that is absurd. Heating water does not increase the TDS but usually decreseses the TDS. It will often increase y the amount of particulates though. Particulates are removed by the prefilters not the RO membrane. The reason that you are suppose to occasionally drain sediment (particulates) from the bottom of a haot water tank is because heating the water removes calcium from the water by making the dissolved calcium into calcium particulates (calcium carbonate).

In short don't rely on pH readings of RO water.

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hot water does have high levels of tds. Mainly because its heated in a large metal drum called a water heater. The lining deteriorates over time, and causes higher tds elvels.

In additional, a standard 75gpd/100gpd ro membrane maxes out at around 110F / 115F. Industrial membranes max out around 140F. 180degrees would melt the membrane....not to mention all the pre-filters along with it.
Test hot water vs cold with a quality tds.

Mongobud said:

I called my hydro shop and the girl there told me that The PH shouldnt be changing at all, if the tap comes out at 7.5, then so will the RO'd water...at 7.5

She said the only thing that the system does, is lower PPM, which is coming out 15 PPM.

Then again this is the same girl that gave me horrible advice once, trying to make a sale.

Does RO water normally make PH fluctuate?

Click to expand...

yeh, that sounds like bs. ro/di water will have 0 ppm and a neutral ph level. 7.0 point on.

my ro system is 0 ppm but the ph is 4.3

southern homegrower said:

my ro system is 0 ppm but the ph is 4.3

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what pre-filters (kind and ppm rating)are you running on the ro and how old are they?

are u also running a water softener or have a water softener on your house water?

u think thats messed up if i make 5gals. of ro water it wiil make 55gals. of waste water

southern homegrower said:

u think thats messed up if i make 5gals. of ro water it wiil make 55gals. of waste water

Click to expand...

that is a bit off. a 1:10 ratio is a bit high. some older membranes run at those, but most new models operate somewhere in the 1:3 to 1:5 range.

But what i suspect you have is inadequate water pressure going into the unit. Its causing your unit to waste more water.

Do you have a pressure gauge on your ro?

i dont want to hijack this mans thread so i sent u a pm