New to dwc. Ppm problems please help!

So im not even 100% sure this is a problem yet but im confused about the ppm reading im getting. When i add general hydroponics ph down (powder) to my water it raises my ppm reading. I have been reading on here that other people have the same issue.
Im wondering how i am to follow any type of feeding schedule or really know what my plants are using if the ph buffer is adding ppms.
 

particle

Well-Known Member
Some use nitric acid for veg, which is N, and some use phosphoric acid for flowering, which is P. They won't change your PPM reading, but they obviously are changing your feeding ratios. You could try compensating for it, but I've yet to see anyone do that. It's probably not worth the stress or effort. Plants still grow... etc.

Gh PH down is not that great though, I don't think. It uses a variety of acids, which may even do more to keep the ratios in check. But the citric acid in it doesn't help stability and bacteria can feed on it causing a bloom.

Anyway, once you establish your res with all the ratios you were hoping for, it doesn't stay that way. The plants will start taking what it wants from it. It would be interesting to see some real data on what the expected variance should be under standard and even different conditions. Someone, like a professional botanist, probably knows, but I've never seen that info.

I would chalk it up to "not a big problem" and push on. Just worry about keeping your res healthy (keeping your roots healthy), and just make sure that your PPM's drop over time rather than rise. That's all you need to know that your plants are content.

You could have everything perfect, with your PPM's dropping, and then pull a few big leaves off and the next thing you know they're rising. Point is it's constantly variable and you can never know what your plants are using exactly at any given time, other than some portions of something you gave them. Just monitor and know what to look for.
 
Im now on day seven from taking my clones and ive only had ppms drop once. The rest of the time theyve gone up because of my ph down. Or other reasons im not aware of. If phosphoric and nitric acid are P and N how would that not affect ppm? Only one of the four is starting to have roots come out the bottom of the net pot. This whole growing indoors is turnin out to be a real fuckin pain. Nothin but problems since i started, a little over three months ago. I started in soil and those plants have been shit from the begginning and are now infested with super tiny green bugs (root aphids i suppose). Ive been trying to get this hydro going but im totally new to indoor/hydro. And with all the reading ive been doin i dont understand how i didnt come across the ppm rise cause by gh ph down. Idk im so frustrated right now. Thankyou for your advice tho much appreciated.
 

Hydroburn

Well-Known Member
I have been using the dry powder too and you are right, it fucks up ppm. Try different ph down... I haven't had issues with the liquid ph down from GH or Technaflora.
 
Last edited:
Top