Preparing water PH for new clones

[RandyL]

I'll be starting some clones in the next day or 2, and I'm getting the water ready now. My local water (Los Angeles city water), tastes terrible and has a PH around 7.5 on my PH meter.

A place across the street has a big filter and machine setup, and makes the RO water. I was planning to get that, adjust the PH, and use that to water the clones for the first 2 weeks until it's time to start adding fertilizers.

I'm using Fox Farms Ocean Forest soil, and I've seen their fertilizer schedule, wherein it says to keep the PH in the 6.3 to 6.8 range.

I was planning to set my RO water PH to 6.5 . Does that sound like a good safe number to use? I'm not sure what the PH of the actual soil is. Could not afford to buy every single kind of meter to get started with.

[Screwnuts33]

Randy,
That sounds safe. You can also try a little test run. Run some of the PH'd R/O water through your soil and test the PH level of the run off.

[RandyL]

Got 5 gallons of RO water from a local water place today. In a new blue jug from them. I put a little of it in a paper cup, and the PH tested at 6.62 with nothing added.

I put a gallon of it in a plastic 1 gallon jug, and it's showing right around 6.45 to 6.50 PH.

I had washed out the 1 gallon jug with Ajax orange antibacterial dishwashing soap and rinsed it with both hot and cold water several times, I'm guessing that's why the PH shows up a little different.

But this is good so far, I should not have to do any PH modifications on days where the plants get water only. I'll still PH test it each time, though.

Somehow I thought RO water would be 7.0 .

My tap water is around 7.50 PH.

Here's another question on adjusting the PH. I practiced for a while on a 1 gallon jug of the RO water. I was surprised how a few drops too much can really throw the PH all to fcuk and back.

Say you have a gallon of 7.0 PH water. You add some PH down to drop it to 6.5 . Oops, too much, you're at 5.7. Okay, add some PH up and DAMN, it's maxing out the range of the PH meter, bouncing around 9.9-10! All right, a few more drops of PH down to pull it back down again... Okay we got it at 6.5 somehow now.

The question : is there now too much of the PH adjusting stuff in the water to safely use on the plants? The bottles say Potassium Hydroxide and Phosphoric Acid. I can't imagine that being good for plants in large quantities!

[LabRat420]

Originally Posted by RandyL

Got 5 gallons of RO water from a local water place today. In a new blue jug from them. I put a little of it in a paper cup, and the PH tested at 6.62 with nothing added.

I put a gallon of it in a plastic 1 gallon jug, and it's showing right around 6.45 to 6.50 PH.

I had washed out the 1 gallon jug with Ajax orange antibacterial dishwashing soap and rinsed it with both hot and cold water several times, I'm guessing that's why the PH shows up a little different.

But this is good so far, I should not have to do any PH modifications on days where the plants get water only. I'll still PH test it each time, though.

Somehow I thought RO water would be 7.0 .

My tap water is around 7.50 PH.

Here's another question on adjusting the PH. I practiced for a while on a 1 gallon jug of the RO water. I was surprised how a few drops too much can really throw the PH all to fcuk and back.

Say you have a gallon of 7.0 PH water. You add some PH down to drop it to 6.5 . Oops, too much, you're at 5.7. Okay, add some PH up and DAMN, it's maxing out the range of the PH meter, bouncing around 9.9-10! All right, a few more drops of PH down to pull it back down again... Okay we got it at 6.5 somehow now.

The question : is there now too much of the PH adjusting stuff in the water to safely use on the plants? The bottles say Potassium Hydroxide and Phosphoric Acid. I can't imagine that being good for plants in large quantities!

Both of those chemicals break down into stuff your plants can use. Potassium hydroxide supplies some K and the phosphoric acid supplies some P. Two parts of the NPK that make up all fertilizers.

pH is tricky to get right on. I start my DWC with RO or distilled water, add SiO2 (silicon dioxide or Liquid Rock), and the pH goes up to 10.5. I then bring the pH down to around 6 before adding nutes then adjusting to around 5.6. I use concentrated Sulfuric acid to pH down and a bit more SiO2 if I have to go back up.

Try diluting your pH stuff 10 to 1. Then a few extra drops won't make your pH bounce around so much. If the water you're using is around 6.5 I wouldn't even adjust it. Most soil mixes are slightly acidic and will pull the pH down a bit anyway. Like Screwnuts33 said, "run some water through the soil your using and test the run-off water". I would add that you maybe mix up a small batch of nutes in the proportion you plan to use when growing. Run that through some of the soil until saturated, test that, then add some more in 24 hours and re-test. It can take some time for the pH to get steady when everything is first mixed together.

I've also noticed that more plants get sick or die when the grower obsesses about the pH and constantly tries to keep it dead on. My DWC goes from 5.2 to 6 and if I leave it alone the girls do just fine.

You have to realize that the water and adjusters you are experimenting with have zero buffering capacity and react very quickly every time you adjust up or down. Try putting some nutes in a small amount of water, let it sit for 20 min, then test. See if adding your diluted pH up or down dropwise doesn't give you finer control of pH changes.

RO water and quality nutes should be fine without adjustment unless your soil pushes the pH up or down too much.

PS: to clean your jug just fill with hot tap water then add 1 or 2 drops of soap to act as a surfactant then add a cap-full of unscented Javex. Let it sit for a while then dump it out and add your RO water. No rinsing required. ditch the antibacterial soap for Dawn. A couple of drops per gallon every few jugs of your nute water will help it soak in evenly getting rid of dry areas in the pot.

Good luck with your grow dude.

[RandyL]

Thanks for the tips, diluting the PH adjuster solutions 10 to 1 sounds like a good idea. I just need to find some small containers to put the mix in.

Plants are due to arrive today, so it'll be time to get this grow started! I'll have to start a grow journal in that forum section!

[LabRat420]

Originally Posted by RandyL

Thanks for the tips, diluting the PH adjuster solutions 10 to 1 sounds like a good idea. I just need to find some small containers to put the mix in.

Plants are due to arrive today, so it'll be time to get this grow started! I'll have to start a grow journal in that forum section!

Use any clean containers you have. Clean glass bottles will be fine. Neither one of those chemicals are light sensitive so clear glass or plastic bottles will work OK. A beer bottle will work too. The proportions aren't important. 7-1, 12-1, no big deal. I'm anal about that sometimes, being a chemist and all, but in this instance it's all about diluting to give allowances for reactivity.

10 -1 just means that you'll have to put in ten drops to get the same result as 1. Gives you a lot more leeway for mistakes. Allow some time before adjustments to let the pH level out. It's easy to add more before the first dose has time to react and end up overshooting the mark. Don't worry if it moves around a bit while growing as that is very normal. It doesn't have to be 0.01 out before you mess with it. Soil grows have a lot of tolerance for pH before things get out of hand. Say 5.8 - 6.8. That's ten times or one magnitude difference in acidity.

Learn to read your girls. Watch the new growth. Old leaves die so you should get rid of them as soon as they look sick. Not light green, but yellow and necrotic. If the top growth looks healthy and sometimes lime green let it progress and it should turn dark green, if not look for problems. Most plants die from neurotic growers than deficiencies. They are weeds after all.

Relax, it'll work out better if you do.