About to start DWC gro, I need confirmation on PH and PPM

bam bam

Active Member
Iam about to start my first grow with DW. I want to know a few things about PH and PPM before I start my grow this way if I run into problems I would know what to do.

I have read that using PH buffered nutrients, lowering your PH to the correct levels before you mix in your nutrients, and soaking your rockwool in a PH neutralized solution or buying PH neutralized rockwool will help you control your PH during your grow. Is this right? what else helps control your PH? I know PH will change but I just dont want drastic changes or swings in PH readings.


Now for PPM. I dont want to spend money on RO water, so will 400 ppm tap water work? If my feeding chart says nutes should be at 600ppm, when I mix it with my 400ppm tap water, my ppm meter should read 1000 ppm?
During seedlings and clones, is it better to use RO water, this way your PPM reading with nutrients are as low as possible? Iam scared high levels of PPM during seedlings and clones will kill the plants.

Anything else I might need to know about PH and PPM before I start my DWC grow?
 

cowboylogic

Well-Known Member
400 ppm tap water is way too high. Most say 150 to 200 is max. I am afraid 400 is going to cause you tons of issues. You can get a good r/o system for under 200 bucks off ebay. Or do as I do in the summer, collect rain water, plants go ape shit over rain water.
 

bam bam

Active Member
400 ppm tap water is way too high. Most say 150 to 200 is max. I am afraid 400 is going to cause you tons of issues. You can get a good r/o system for under 200 bucks off ebay. Or do as I do in the summer, collect rain water, plants go ape shit over rain water.
my tap water is 30 ppm, so its all good.
 

angelsbandit

Well-Known Member
"lowering your PH to the correct levels before you mix in your nutrients" - Wrong! Check the PH after all nutrients are added.
I have very little swing in PH once set until just before time to change out water/nutrients.
 

cowboylogic

Well-Known Member
So how did it go from 400 to 30? I have great well water at 180-200.
Yep, pretty good. Mine is 260 or so and use it when needed without too many issues. But I still like my rain water. Its so easy to collect, least were I live. I can almost cut my nute mix in half with rain water vs. well. So can feed more often without salt buildup. And I guess he did go from 400 to 30. Still wanna know where 30ppm tap is coming from. Thats as low by a longshot from any I have ever seen or heard of.
 

stumps

Well-Known Member
what is the ph in your rain water? We don't get much rain. I was thinking about a mid grow flush with DI water. But don't know if the plants would survive. I use it to clean cal scale off valves and just about anything that gets hard water spots.
 

bam bam

Active Member
"lowering your PH to the correct levels before you mix in your nutrients" - Wrong! Check the PH after all nutrients are added.
I have very little swing in PH once set until just before time to change out water/nutrients.
Yeah I guess checking your PH after you mix in nutrients should also be done.

If I use PH buffered nutrients, and mix it with a PH neutrall water, the PH buffered nutrient shouldnt change my PH value that much. If it does change it would probally be a small change, which would be easy to correct.


Its municple water that gives me 30 ppm. I live on the west coast. The water in our city is very soft.
 

stumps

Well-Known Member
What part of the west coast? I can't remember finding soft water anywhere? just wondering. theres alot of places I haven't been.
 

cowboylogic

Well-Known Member
what is the ph in your rain water? We don't get much rain. I was thinking about a mid grow flush with DI water. But don't know if the plants would survive. I use it to clean cal scale off valves and just about anything that gets hard water spots.
It depends a bit on how long it has been between rain. Think because of moss build up and a few other things. I collect my water from roof run off. But between 6.8 and 7.7 is a norm. And with most feedings it brings the ph down to a nice 6.3 to 6.6. Only when I use alot of organics does it drop low enough to ph up.
 

cowboylogic

Well-Known Member
Yeah I guess checking your PH after you mix in nutrients should also be done.

If I use PH buffered nutrients, and mix it with a PH neutrall water, the PH buffered nutrient shouldnt change my PH value that much. If it does change it would probally be a small change, which would be easy to correct.


Its municple water that gives me 30 ppm. I live on the west coast. The water in our city is very soft.
You shouldnt ph your water, add nutes then ph again. Add your nutes to your tap water then ph. If you add bit much of either (ph up, ph down) it is not a good ideal too use them both to get it right. I mean, do not use ph up and down in the same solution. If you go past your goal either way then start over fresh. Using them both in the same batch of food is only going to cause problems.
 

stumps

Well-Known Member
deionized water. It pulls the cal and mag frorm the soil at least thats my theory. the water runs threw a ro system before it goes threw the di system.
 

bam bam

Active Member
You shouldnt ph your water, add nutes then ph again. Add your nutes to your tap water then ph. If you add bit much of either (ph up, ph down) it is not a good ideal too use them both to get it right. I mean, do not use ph up and down in the same solution. If you go past your goal either way then start over fresh. Using them both in the same batch of food is only going to cause problems.
So what do you do if your PH goes up one day, then you adjust it with PH down, then a couple of days later your PH goes down, could you adjust it by using PH up, without having to completely change your nutrient resevoir?
 

cowboylogic

Well-Known Member
So what do you do if your PH goes up one day, then you adjust it with PH down, then a couple of days later your PH goes down, could you adjust it by using PH up, without having to completely change your nutrient resevoir?
Thats ok, has to be done. But I think you will find as you get the bugs worked out. You will be able to have a pretty stable ph. Just with your initial mix, going up and down, just imo not a good starting point. Things seem to spin out of control faster doing this. But I know people who do and still get fine results. Just not the way I roll!
 
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