DWC ph swing

[budboy299]

Hi gang,

I've grown buckets quite a few times before and never really got into watching ph as I always changed out the nutes every week. Never had a problem either though.
This time I am watching my ph levels in the buckets.
Nutes are mixed to about 75% of recommended amount on bottle, RO water, then ph balanced to 5.6-5.8
by the next day though it will be at 6.8 - 7.0 ph.
I will adjust again with ph down (hydro store purchased)
till I hit mid 5 ph...by next day it is back up again.
Anyone else have this? I do top up with straight water just prior to ph leveling as well and still the drift is that great. Any thoughts on this would be appreciated.
Thanks

 

[rome]

well i just saw in the hydro thread ., about waterfarms they were talking about airstones making ph swings.., best man to talk to about that is hererisssh ., or texas kid check out their diy standalone dwc bucket thread

 

[hererisssh]

What's your water source bb?

 

[kindindy123]

ph drift???

hey buddy, somtimes the plants feeding will make ph rise,just keep adjusting it,its acualy good for ph to drift a little, so plants get full range of nuitriants.in a 24hr period,the plants absorb nuitriants at diff ph levels,it should stablize in a few days,then change in another few days, that would be about 10 days res change cycle. good luck buddy!!!

 

[budboy299]

Not sure how to type your nickname man but my water for the next 2 weeks is rain water with a ppm of around 80 - 90
In 2 weeks I will have an RO system up and running.

thanks guys for getting back to me. So far it hasn't seemed to make the plants suffer but I would rather be proactive than not. Again thanks

 

[hererisssh]

What are the nutrients you're using and what amounts? Are you using Cal/Mag with the rain water?

 

[cemchris]

Temp of the water has alot to do with it also. Keep track of the water temps to give you an idea.

 

[FastForward]

I've had big pH swing probs, but they were probably down to silting hydroton. I filtered the res through a 100 micron filter to remove all the silt and then put it back in again - pH stayed level.

I also find that root stims like Rhizotonic when used with an airstone in a res can cause pH rises (e.g. 5.5 to 6.5 in 24 hours). I use a circulating pump in the res instead of an airstone to oxygenate/circulate the nutes and the pH stays relatively solid. I'm in a hard water area...no RO, no rain.

HTH

 

[budboy299]

No Cal-mag yet...all the area hydro shops are sold out. I ordered off the net but it will be a week till I get it.
The rez is 5 gallon buckets with DWC. Nute solution is 3 gallons.
Rez temps range from a low of 62 degrees to about 70 degrees max by end of light cycle. Black buckets so maybe I will tape the tops with reflective tape.
No algae in buckets at all which is great!
The hydrotron did silt a bit for the first couple nute changes but seems to have stopped.
Each nute change I clean the buckets with hot water and a biodegradable soap. I make sure all soap residues are completely gone as well.

The first couple days after a change are the worst.
The nutes are a local brand with an A and B, 20ml of each per gallon thing
I have also been putting some epsom salts in with this at 1tsp/gallon for a possilbe MG defficiency till I get the Cal-mag(this is only done once per nute change)

When I first add the nutes...plain water is at 7.8 ph, then with nutes if plummets to 4.8 ph. After a day it is mid 5 ph. Sad part is though it continues to climb the next day to 7.2 I will bump it back to mid-5ph and sure enough the next day will be up again. Although every days bump it seems to have less swing than the day before.

ppm stay fairly constant and I have only ever been topping up with ph balanced water.

I guess it is something I will live with for now as the plants don't seem to suffer but it sure is a mystery.

I think I will ph balance some of my plain water to see if it is something to do with the fact is rain water or if its the ph down that just doesn't want to hold.
At least that way I can narrow the variables down.

thanks guys for the help and the suggestions