PH and PPM fluctuations. Advise needed (DWC)

Dandx13

Member
Hi everyone,

I am very much new to growing, as this is my first grow and I am only 1 week since planting. My PH seems to be climbing must faster than natural as I am not seeing my PPM fall nearly at that pace. I have changed the water completely at 5.6 PH and 340 ppm and within 2 days my PH will be at 6.5 and ppms are steady or even up a little bit. Im suspecting it may be hydroton dust because it has gotten in the water and Ive cleaned out the reservoir twice already. (I soaked them for 5 days but never power washed them.

Any Help is greatly appreciated!! Attached is a picture of my log.

my setup:
2 very young plants in 2 inch netpots inside one 1 gallon reservoir. Germinated in Rockwool and surrounded by hydroton. Yes I am starting very small to get my head around it all.
 

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MustGro

Well-Known Member
It's not unusual for your PH to fluctuate; especially with a fresh tank. Mine will move around the first day or two. You get used to it and know which way it'll go. It takes time for the plants to take up PPMs, you won't see a big change unless you have a lot of plants or a small resservoir.
So my tap water is 7.5 PH. If I'm not using a strong dose of nutes like you (340 PPM) my tank will be 6.5 ish after it's filled. I like the Cyco brand PH adjusters, but they're strong. A few ml will drop my tank to 5.8 or so. It will probably move a bit in 24 hours and I'll correct it again. Then it's usually pretty steady for the next week. I might add a few ml a day if the plants are using a lot of PPM.
I use Hydrotron exclusively. Hydrotron dust is not a PH problem. Hydrotron and all hydro clay is PH dependent. It offers zero ability to buffer the PH in your solution. Materials like humus or sphagnum peat moss are PH independent and can buffer PH.
In hydro try to keep your PH between 5.4 and 5.8. A PH over 6 can lock iron out and a PH under 5 will make iron and manganese toxically available.
 

Dandx13

Member
It's not unusual for your PH to fluctuate; especially with a fresh tank. Mine will move around the first day or two. You get used to it and know which way it'll go. It takes time for the plants to take up PPMs, you won't see a big change unless you have a lot of plants or a small resservoir.
So my tap water is 7.5 PH. If I'm not using a strong dose of nutes like you (340 PPM) my tank will be 6.5 ish after it's filled. I like the Cyco brand PH adjusters, but they're strong. A few ml will drop my tank to 5.8 or so. It will probably move a bit in 24 hours and I'll correct it again. Then it's usually pretty steady for the next week. I might add a few ml a day if the plants are using a lot of PPM.
I use Hydrotron exclusively. Hydrotron dust is not a PH problem. Hydrotron and all hydro clay is PH dependent. It offers zero ability to buffer the PH in your solution. Materials like humus or sphagnum peat moss are PH independent and can buffer PH.
In hydro try to keep your PH between 5.4 and 5.8. A PH over 6 can lock iron out and a PH under 5 will make iron and manganese toxically available.
Appreciate all the advice. Im currently using Advanced Nutrients PH perfect 3 part nutes. Do you think 340 PPM is too high for this early in the grow? If you could share you're PPM scheduling that'd be great!
 

MustGro

Well-Known Member
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Did that work all right.... Advanced doesn't put their charts online anymore.
So all the doses are in the chart; I'm not sure of the PPM it'll give you. It'll depend on your source water.
I used gen hydro a lot but just switched to Jack's. In GH your dose of 340 would be low; in Jack's it would be high. How about a pic of the plant and setup.
 

Dandx13

Member
View attachment 4938153
Did that work all right.... Advanced doesn't put their charts online anymore.
So all the doses are in the chart; I'm not sure of the PPM it'll give you. It'll depend on your source water.
I used gen hydro a lot but just switched to Jack's. In GH your dose of 340 would be low; in Jack's it would be high. How about a pic of the plant and setup.
Small box set up. 1 week in the box right after the seeds popped a little in the paper towel method. Heres a few pictures. D6B199C4-0545-47C9-AD8F-B50CDBB25821.jpeg
 

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GBAUTO

Well-Known Member
What I can tell you from my hydro experience is size matters...
Trying to keep a stable rez when working with just a gallon of volume is going to be fun.
 

MustGro

Well-Known Member
Yeah it's a little on the small size but it's doable. Watch your room temps as a small res will swing in temp fast.
You know, if I was using the PH perfect 3 part I don't think I'd worry about the PH too much. According to them it's supposed to be "perfect" for a week. I know they're the one brand I can name that says you don't need cal/mag with their base nutes either.
Your grow space looks cool; the seedlings are in good shape; tips aren't burnt, not too lime green; they have a nice dark green tint in places too.
I'd say carry on with what you're doing. Don't sweat the PH too much unless you want to, and watch them for changes.
 

Dandx13

Member
Yeah it's a little on the small size but it's doable. Watch your room temps as a small res will swing in temp fast.
You know, if I was using the PH perfect 3 part I don't think I'd worry about the PH too much. According to them it's supposed to be "perfect" for a week. I know they're the one brand I can name that says you don't need cal/mag with their base nutes either.
Your grow space looks cool; the seedlings are in good shape; tips aren't burnt, not too lime green; they have a nice dark green tint in places too.
I'd say carry on with what you're doing. Don't sweat the PH too much unless you want to, and watch them for changes.
Appreciate all the advice MustGro! I keep a daily log as this is my first grow so I want to see how things go. On the other hand I am going a lot bigger for my next one and getting a 3x3x6 tent and a mars hydro tsw2000 (300 watt) light. Super excited for that
 

MustGro

Well-Known Member
Daily logs are great; I keep one. Hydro is a hard beast to learn on; things can go to shit real quick on you. Don't ignore changes in your plants; especially when they're this young. Hydro will definitely yield better than soil in my experience; and I think it's a lot easier to do.
 
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