DWC PH question

[Drew341]

I have a question regarding high ph fluctuations day to day I am worried that girls are not up taking nutrients like they should having to add water daily to adjust EC and ph. I just looking for some advice not sure if I am getting all I could be.

lemon haze
3X5.
2 450w full spectrum leds
1 300w full spectrum led
2 5 gallon dwc bucket
week 4 flower
emerald harvest 2 part feed chart
Bulletproof SI 2 mls per gallon
photo synthesis plus 6 mls per gallon
water ph to 5.8-6.0
EC 1.8 at last feeding starting week 4

[Cannabliss]

One of the things I learned from years of growing in DWC is that the smaller the container, the harder it was for me to control pH fluctuations. I would transplant them into 5-gallon buckets rather than keeping them in those 2.5 gallon buckets. The roots, along with the air stones can make things pretty cramped in there. I’m guessing that may be one of the culprits. Another could be the air coming in from the air pumps. If your air pump is pretty hot or the hoses are exposed to the heat of the lights, some hot air can escape into the reservoir and cause pH fluctuations as well. Everything else seems to be about right. May want to also consider raising those LED a bit. They look too close to the canopy. Welcome and good luck.

[gbauto]

Welcome, Drew.
Like Cannabliss noted, as the plants develop a root mass it will reduce the amount of solution in the bucket and you will get some ppm and pH changes-kinda goes with the system. I run a couple of DWC buckets each winter downstairs while the primary grow is running in my main room. I do this to sample different strains. I have used GH Flora trio and MegaCrop, my well water is 6.7 and less than 50ppm. The buckets will usually settle around 5.5 and stay there. I tend to only raise the pH over the 10-14 days between fluid changes-I let it rise to 6.5 as the week progresses. Usually, big pH changes indicate a root issue but if it's only a few tenths I wouldn't try and make it perfect. Small adjustments seem to work best for me.

[Drew341]

Thanks guys for the info I have them in 5gal buckets with 4gal of solution in them running 2 air stones per bucket going to 7 gal square buckets next round.The lights I know are close had to extend veg to not be at harvest while on vacation looking at going with 615 LEC in future.

[Drew341]

Keep water temp @ 68-70

[ocgreen]

water ph to 5.8-6.0

PH should be 5.5-6.5

Not saying this is what you did, but be careful making micro adjustments to ph (e.g. trying to keep between narrow range of 5.8-6). I was doing something similar and my plants suffered. Now I let it swing more naturally as long as it stays between 5.5-6.5

[Drew341]

5.8-6 is my optimal target at water change weekly. My ph is going from 5.8/6 range to like 4.5-5.0, and EC from 1.8 to over 2 the next day. Water level will be about 1 gal low so it seems they are up taking water but not nutrients.

[ocgreen]

I'm new to growing so take this with a grain of salt, but if you're experiencing a situation where you are starting your reservoir at 5.8-6 and it's dropping to below a healthy range (e.g. 4.5-5) then I would say it makes logical sense to start your reservoir at top of appropriate range (6.5) and let it drop. Sounds like it would drop to what you see as ideal range instead of 4.5-5.

[abadtrip]

Ok lots of advise u got there i grow in hydro don't know how to grow in dirt. My ph goes up in veg and down in flower i top up with just water during the week. I try and start at the high end of the range 6.5 5.5 When I change res.
now u ask the question about if your plants are taking up more water than nutes no they are not. From all my research and it's not alot I am not a scientist but try and follow scientific principals. Roots work of of osmosis moving H O and all the others u put in there like P K N. From the water to the plant. Now if your water gets to high in nutes u will start to reverse the osmosis and the plant will start moving vital nutrients back into the water and kill the plant.
My plants drink 15 gal a week each in full flower so soon u may be adding water so often u won't even notice the ph flux.

[Iammygod]

Maybe you are using nutrient that has been formulated for hard water but you use RO water.
Try more Alkalinity by adding 50-100 milligram baking soda per gal of solution then lower the ph using phosphoric acid or something if needed. The reaction goes slowly so wait an hour or so before measuring and adj ph. It's hard to control ph drop during heavy flowering without having enough Alkalinity.