First DWC grow, little insight?

[Twistedmistersartz]

So doing my first dwc. Things seem to be going pretty good. Plants are in their 2and week of flower. My question is, when I do a res change, over the next couple days water levels drop. Ppm drops. Ph rises. Normal right? But after a couple days the ph starts to drop ppm goes up and water levels drop. Im topping off water everyday and ph'ing twice a day to stay withing range. Which I dont mind but why the shift in numbers after a couple days? I've got the ec/ph/water level chart. It mentions something about acid rain effect? What's that. Tia for any help!

 

[Hydroholic]

PH in DWC is something, depending on Nute line that has to be dealt with constantly. I use an auto doser to monitor PH and adjust accordingly. You should be refilling with nutrients each time and not just water or this will drop your EC and change PH at the same time.

 

[Twistedmistersartz]

PH in DWC is something, depending on Nute line that has to be dealt with constantly. I use an auto doser to monitor PH and adjust accordingly. You should be refilling with nutrients each time and not just water or this will drop your EC and change PH at the same time.

So add nutes even if I'm adding water every other day? I wasnt sure. Thanks for the advice.

 

[HiighTide]

So doing my first dwc. Things seem to be going pretty good. Plants are in their 2and week of flower. My question is, when I do a res change, over the next couple days water levels drop. Ppm drops. Ph rises. Normal right? But after a couple days the ph starts to drop ppm goes up and water levels drop. Im topping off water everyday and ph'ing twice a day to stay withing range. Which I dont mind but why the shift in numbers after a couple days? I've got the ec/ph/water level chart. It mentions something about acid rain effect? What's that. Tia for any help!

I’m only 3 months into my 1st grow (rdwc) so I’m no pro (yet), but I feed water only at times to bring ppm back down. DWC can definitely be a bitch at times but a beautiful thing when dialed in.
Acid rain effect comes with high C02 levels. You probably could rule that out if you’re not enriching.

 

[Rifleman]

Hope this helps.

DWC/Fem Seed Tutorial

 

[Hydroholic]

So add nutes even if I'm adding water every other day? I wasnt sure. Thanks for the advice.

In dwc you should be changing nutrients once a week. Doubtful you will have to top off each day. When you top off it needs to be the same mix you have in there. Not just water. After a few times you will find out how much the plant drinks and mix enough for that whole week.

 

[Twistedmistersartz]

In dwc you should be changing nutrients once a week. Doubtful you will have to top off each day. When you top off it needs to be the same mix you have in there. Not just water. After a few times you will find out how much the plant drinks and mix enough for that whole week.

They're drinking almost a gallon a day

 

[straightup]

So doing my first dwc. Things seem to be going pretty good. Plants are in their 2and week of flower. My question is, when I do a res change, over the next couple days water levels drop. Ppm drops. Ph rises. Normal right? But after a couple days the ph starts to drop ppm goes up and water levels drop. Im topping off water everyday and ph'ing twice a day to stay withing range. Which I dont mind but why the shift in numbers after a couple days? I've got the ec/ph/water level chart. It mentions something about acid rain effect? What's that. Tia for any help!

You should always allow your PH to drift within a certain specified range, rather than constantly adjusting it to one specific ph value.

Nutrients absorb at different ph levels therefore you want your nutrient solution to experience a range of values for optimum absorption. Ie. Don't constantly micro manage your ph levels to 5.8 or whatever you are using. Adjust it when it hits 5.5 or 6.5 either up or back down.

 

[RaggedyMan]

When in late flower my pH can drop drastically overnight (lights on). A couple days ago it went from 6.2 to 5.1. Does it ALL THE TIME. After a rez change it'll be good for a couple days. I always end up with good grows, I just buy pH up by the gallon. Finishing up a grow now, next one I'll be plumbing in a 30 gallon tote to increase solution capacity, maybe that will help.

 

[Twistedmistersartz]

When in late flower my pH can drop drastically overnight (lights on). A couple days ago it went from 6.2 to 5.1. Does it ALL THE TIME. After a rez change it'll be good for a couple days. I always end up with good grows, I just buy pH up by the gallon. Finishing up a grow now, next one I'll be plumbing in a 30 gallon tote to increase solution capacity, maybe that will help.

Yeah mine is all over the place. I set it and let it drift then bring it back. Switch from 3.5 to 5 gal buckets helped. A big res for all of them would be sweet. Thanks for the comment.

 

[RaggedyMan]

Yeah mine is all over the place. I set it and let it drift then bring it back. Switch from 3.5 to 5 gal buckets helped. A big res for all of them would be sweet. Thanks for the comment.

I now have 2 40 gallon totes with 3 plants each. Once into flowering I can only get 15 gallons in each one because of the root mass so that's really only 5 gallons per plant. I'm plumbing those 2 and the 3rd tote together for 3 reasons. First is the larger capacity to help regulate pH and ppm, second is so I don't have to keep moving my chiller hoses back and forth and third I recently bought a bluelab pH/tds guardian so I don't have to keep crawling around under the plants getting water samples out of both totes. Going to make growing so much simpler especially since I have to monitor the pH several times a day.

 

[Twistedmistersartz]

I now have 2 40 gallon totes with 3 plants each. Once into flowering I can only get 15 gallons in each one because of the root mass so that's really only 5 gallons per plant. I'm plumbing those 2 and the 3rd tote together for 3 reasons. First is the larger capacity to help regulate pH and ppm, second is so I don't have to keep moving my chiller hoses back and forth and third I recently bought a bluelab pH/tds guardian so I don't have to keep crawling around under the plants getting water samples out of both totes. Going to make growing so much simpler especially since I have to monitor the pH several times a day.

That sounds amazing. I'm dragging my plants out twice a day to do ph checks. Haha

 

[The Germinator]

I’d say add nutes. Raise ppm. Should straighten out

 

[The Germinator]

This chart works. Spot on. Enjoy.

 

[HiighTide]

I now have 2 40 gallon totes with 3 plants each. Once into flowering I can only get 15 gallons in each one because of the root mass so that's really only 5 gallons per plant. I'm plumbing those 2 and the 3rd tote together for 3 reasons. First is the larger capacity to help regulate pH and ppm, second is so I don't have to keep moving my chiller hoses back and forth and third I recently bought a bluelab pH/tds guardian so I don't have to keep crawling around under the plants getting water samples out of both totes. Going to make growing so much simpler especially since I have to monitor the pH several times a day.

Update us when the results are in. I’m ending my 1st grow and it’s In RDWC (4-5gal) the ph drop through flower is nonstop for me with such a small volume of water. Oh and the 8” net pots aren’t making it any better lol, I barely get 6 gal out the chiller when changing water.
We grow and learn though.

 

[BirdieNumNum]

I use large single rez which is several times larger than the standard buckets most use.

Fewer changes and easier to manage water temps but when you screw it up - lot more water and nutes involved for me.

 

[RaggedyMan]

Update us when the results are in. I’m ending my 1st grow and it’s In RDWC (4-5gal) the ph drop through flower is nonstop for me with such a small volume of water. Oh and the 8” net pots aren’t making it any better lol, I barely get 6 gal out the chiller when changing water.
We grow and learn though.

I forgot about this post until Birdie chimed in.
My "new" system is working nicely. Tds & ph monitor is spot on, chiller keeping all 3 totes cool as a cucumber (I wrapped them in insulation) and the added gallons of nutrient solution are allowing me to go 2 weeks without a ph problem, maybe 3 if I add nearly 2 Tbsp of ph up every couple of morning but I don't like doing that. When I change nutes I'll set the ph at upper limits and let it drift to 5.6 or so. The ppm is at 520 (.5 scale) as they are autos and burn any higher. Right now they are taking nearly 3 gallons a day (lights on 24/7) and every morning I'll add whatever is needed to keep it at 520. There is a device that is said to keep the ph stable but it's kind of pricey. I had thought about trying it but should it work I would get lazy with the rez changes. I can't think of the name right off hand but if somebody's interested Ill look for it.