RO Water

Medicated Bonsai

Well-Known Member
My tap water is around 270 PPM so I was advised to pick up a filter (by members on RIU). I flushed the membranes this morning for 45 minutes and collected about 4.5 gallons of RO water.

The PPM came out to 70 but the PH was around 9+. Could my PH meter be defective (Dr. Meter PH-100)?

I doubled checked with the Ph UP / Ph DOWN liquids and the color came out to a very light green. The color matched the PH level of around 6.0.

Not sure which method of testing would be more reliable / accurate.
 
My tap water is around 270 PPM so I was advised to pick up a filter (by members on RIU). I flushed the membranes this morning for 45 minutes and collected about 4.5 gallons of RO water.

The PPM came out to 70 but the PH was around 9+. Could my PH meter be defective (Dr. Meter PH-100)?

I doubled checked with the Ph UP / Ph DOWN liquids and the color came out to a very light green. The color matched the PH level of around 6.0.

Not sure which method of testing would be more reliable / accurate.
The drops are accurate r/o water is usually around 5.5-6.0 and your tap water is fine@270ppm,maybe cut it to 150 that’s a good starting point to mix nutrients.
 
You can't do it on the cheap and expect to get good results.....with that being said, but a real pH meter, forget those crappy drops/color match up. And a decent r.o. device has at least 3 filters, and 4 is even better. My ppm is well over 300 before running it thru, and around 30 ppm after words. pH is more random, and it shouldn't be an issue after you adjust it.
 
My tap water is around 270 PPM so I was advised to pick up a filter (by members on RIU). I flushed the membranes this morning for 45 minutes and collected about 4.5 gallons of RO water.

The PPM came out to 70 but the PH was around 9+. Could my PH meter be defective (Dr. Meter PH-100)?

I doubled checked with the Ph UP / Ph DOWN liquids and the color came out to a very light green. The color matched the PH level of around 6.0.

Not sure which method of testing would be more reliable / accurate.
Is that city water if so good thing you got an ro setup. If like me it’s well water then I use mine which is right at 200 ppm. However to answer your question I have 6 stage ro setup I use on my sink to filter everything coming from my water softener ( and before anyone asks I have a separate line running for my rooms to get raw water from the well) but anyways the ph will go from 7 to like 9 ph. Your meter is most likely correct.
 
Is that city water if so good thing you got an ro setup. If like me it’s well water then I use mine which is right at 200 ppm. However to answer your question I have 6 stage ro setup I use on my sink to filter everything coming from my water softener ( and before anyone asks I have a separate line running for my rooms to get raw water from the well) but anyways the ph will go from 7 to like 9 ph. Your meter is most likely correct.
Yea, its city water and damn I bet that RO system was pricey haha. I bought the Hydro Logic Mirco 75. It's only a 2 stage filter but hopefully its better than using tap water.

Thanks for your input guys, I wanna keep using this PH meter since I paid like $40 for it haha. I'll just keep an eye on things for a bit.
 
Yea, its city water and damn I bet that RO system was pricey haha. I bought the Hydro Logic Mirco 75. It's only a 2 stage filter but hopefully its better than using tap water.

Thanks for your input guys, I wanna keep using this PH meter since I paid like $40 for it haha. I'll just keep an eye on things for a bit.
Mine is from culligan an just for drinking. If in doubt the drops don’t lie.
 
Why is high PPM tap water so bad if you are taking that number (background) off of your total nutrient PPM.
 
Why is high PPM tap water so bad if you are taking that number (background) off of your total nutrient PPM.
It all depends on what’s in it. Mine is from my well and I know it’s all calcium, some iron and magnesium so I use mine and do some math. But for city water nah I wouldn’t use it. You can get water reports but I wouldn’t trust them my brother in law works for the city water commission and yah I’m good. There’s a reason it smells like pool water with all the chlorine they use.
 
To clarify, I use well water. I live on an old peach farm, and the soil is loaded with chemicals, lead and other heavy metals and lots of other nasty stuff. It's undrinkable. In hydro, the pH needs to be a lot more exact than in soil, as the soil acts as a buffer. Normal pH is hydro should be around 5.6-5.8 and in soil or pro-mix, ideal is around 6.2-6.3. I use a table top r.o. unit with 4 filters from www.freedrinkingwater.com and the filters are very high quality and last about 1 year before you need to change them. So you know, to replace the cal/mag that the filters removes, I need to add 10 ml of cal/mag with every gallon of water I mix up.
 
I stopped wasting my money on digital ph meters and the drops work just fine even for hydro, no wondering if my pen is bonk

a little chlorine in the water is actually not a bad thing unless your organic or if your using beneficial bacteria and in which case you could fill buckets and let it sit a while and or add some h202 and wait 24hours

your tap shouldn't have more than 5ppm chorine and 270 ppm isn't the worst ive seen gorwers use without issue *(depending on whats in it )

if your filter is bringing it down to 70ppm that's actually pretty good

and
if your growing in soil you don't need to ph the watering solution, its buffered with lime
 
I stopped wasting my money on digital ph meters and the drops work just fine even for hydro, no wondering if my pen is bonk

a little chlorine in the water is actually not a bad thing unless your organic or if your using beneficial bacteria and in which case you could fill buckets and let it sit a while and or add some h202 and wait 24hours

your tap shouldn't have more than 5ppm chorine and 270 ppm isn't the worst ive seen gorwers use without issue *(depending on whats in it )

if your filter is bringing it down to 70ppm that's actually pretty good

and
if your growing in soil you don't need to ph the watering solution, its buffered with lime
So I don't need to pH anything if i'm growing in soil? I feel like there's a lot of false information going around if this is the case haha. I've seen some people get pH/moisture meters for their soil as well.
 
So I don't need to pH anything if i'm growing in soil? I feel like there's a lot of false information going around if this is the case haha. I've seen some people get pH/moisture meters for their soil as well.
No there’s more than enough buffers in good soil which will buffer the ph in either direction hell coco mixes even have buffers. I only ph my rdwc that’s it.
 
So I don't need to pH anything if i'm growing in soil? I feel like there's a lot of false information going around if this is the case haha. I've seen some people get pH/moisture meters for their soil as well.
you can test the ph of your soil to make sure its in range and to determine if you should amend with lime vs gypsum if using organic amandments

they both add calcium but lime will increase the soil ph where as gypsum will add calcium but not affect soil ph

but theres no need to ph adjust the water or fertilizer solution that your feeding with because it wont change the ph of the soil = buffer

in hydro

rockwool, coco, aero, dwc, grow rocks all those require ph adjusting the solution because they don't buffer, (unless on the rare occasion someone adds lime to coco I suppose but I don't have experience with that)
 
No there’s more than enough buffers in good soil which will buffer the ph in either direction hell coco mixes even have buffers. I only ph my rdwc that’s it.
you can test the ph of your soil to make sure its in range and to determine if you should amend with lime vs gypsum if using organic amandments

they both add calcium but lime will increase the soil ph where as gypsum will add calcium but not affect soil ph

but theres no need to ph adjust the water or fertilizer solution that your feeding with because it wont change the ph of the soil = buffer

in hydro

rockwool, coco, aero, dwc, grow rocks all those require ph adjusting the solution because they don't buffer, (unless on the rare occasion someone adds lime to coco I suppose but I don't have experience with that)
Sounds good, thank you. I'm gonna stop pH testing my water and see how things go. This is new to me but it makes things a little easier haha.
 
My tap water is around 270 PPM so I was advised to pick up a filter (by members on RIU). I flushed the membranes this morning for 45 minutes and collected about 4.5 gallons of RO water.

The PPM came out to 70 but the PH was around 9+. Could my PH meter be defective (Dr. Meter PH-100)?

I doubled checked with the Ph UP / Ph DOWN liquids and the color came out to a very light green. The color matched the PH level of around 6.0.

Not sure which method of testing would be more reliable / accurate.
Keep in mind ph is also temperature dependant so if you check and cross check using different methods to verify try to do it when the water is at the same temperature or you will get different numbers (as water temperature increases ph should decrease)
https://sciencing.com/effects-temperature-ph-water-6837207.html
Some good info that helps illustrate this.

Good luck and happy growing!
 
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