Constantly battling pH drop

[mbkboy]

Could be a neutral or beneficial micro organism that has little effect on the plants. When these organisms eat the nutrients, the by product coming out could be altering pH. Many dwc have micro organisms thriving in them, but are undetected due to size and the fact they don't alter much what we measure.

H202 runs should be done with 30% solution diluted at roughly 5ml/5-10ml depending on severity of the situation and size of plants.

How many watts of air supply are you running litre of water? Should have a 1 watt to 2 litre ratio atleast for maxmium o2 (plus extra bubbles dont allow stagnant water)

And change your water pump times! You run a water chiller so heat is no issue! Should be coming on every 5-10 mins to allow proper mixing of the solution.

 

[MrShpongle]

How many watts of air supply are you running litre of water? Should have a 1 watt to 2 litre ratio atleast for maxmium o2 (plus extra bubbles dont allow stagnant water)

And change your water pump times! You run a water chiller so heat is no issue! Should be coming on every 5-10 mins to allow proper mixing of the solution.

I'm running 112 watts of air pump for 250 liters of water, so I'm right at your 1 watt for 2 litre ratio. The system is a combined ebb'n'flo/RDWC; the buckets normally hold 1.5 gallons of nutes, and every 3 hours they are flooded to 3.5 gallons for 30 minutes, then drained back to the rez.

I'm confused by "H202 runs should be done with 30% solution diluted at roughly 5ml/5-10ml depending on severity of the situation and size of plants." So you're saying I should use somewhere between a 1:1 and 1:2 ration of H2O2 to water? That seems crazy strong (and expensive as hell when trying to flush a system this big).

 

[machead]

I had the same problem a was ppm was to high.

This what I did. Got rid all additives just base nutes at 480 ppm .5 scale. I to was at 800ppm yes it did still drop each day for 2/3 days I added PH up till got back at 6.1 then it just stays there now.

Now every res change I do still have to PH up each day when lights come on but only for first 2 days then rest week it stays at 6.1

Now my res level is dropping at a very fast rate each day an the ppm have to started to drop only down to 440ppm over the week.

Plants haven't looked better. They are not drinking over 110 litres in 5 days. This is between 12 plants.

So I'd try this as well as if your plants are not massive 7/800 ppm could be to high for them.

 

[Hydrolized]

I also saw this go away once I cut my nutes almost in half, the plants grew and yielded the same as usual, just at 1.0EC instead of 1.8EC.

 

[Skunkpassion]

@hydrolized, do you use tap water or r/o? What nutes do you use?

 

[wantaknow]

use pool shock there is a thread on here ,it will kill the nasties !I ran it in my ebb and grow ,best harvest ever

 

[smithsutton]

I've got a pretty well-dialed in RDWC system that does everything I want except one thing: maintain pH for more than a New York minute. Here's the details.

12 5-gallon buckets
55 gallon rez hooked up to a chiller set at 66 degrees F
Dyna Gro nutes (Bloom, MagPro & Protekt) at 900 ppm
airstones in each bucket + larger stone in rez

When I change the rez out I balance everything to 5.8, and it will stay there for a few days. Around day 5 it starts to drop massively every single day. It can start at 5.8 when the lights come on and 12 hours later be around 4.2! This happens over and over until I change the rez on day 15, then it starts repeating again around day 5. I've used both AN and GH pH Up drops to balance things out, but nothing sticks.

More info: the ppms are remaining solid in the 850-900 the whole time. I top off the rez w/ 2-3 gallons of pH 7 water (120 ppms) each morning to maintain water levels. There is no visible buildup of anything in the buckets or the rez, and the roots look perfect.

I'd like to think that my nutrient solution should be good for more than 5 days. I've considered the possibility of microbial growth in the system, so I've run H202 through the lines in between rez changes, but that hasn't changed a thing.

I'm at my wits end. This has been going on for 18 months, and it's making life difficult. Vacations are a thing of the past...

P.S. This is only a problem in flower.

goto strait ph adj water when the ph starts to drop for 2 days then fresh nutes remember to mix nutes a whole day before change out .. set chiller to 68 .. i havent had a vacation in 12 years .. so suck it up and make that money boy .. lol ..

ss .

 

[Sativa Dragon]

Sounds like your city water is part of the problem, it is a myth that city water never changes, it will change seasonally with temperature. Treatment plants have to add coagulants to cause solids to drop out of solution. These coagulants plus chlorine chloramine and if your city adds fluorine for dental health of the population some of these things will end up in your water as you cannot remove chloramine or fluorine. RO filters will not remove chloramine or fluorine. I would definitely go get some RO water and next change out, add some H2O2 as well.

This will eliminate the water issue and let you know whether or not your city water is buffering your PH.

Peace

 

[Sativa Dragon]

When I say eliminate I mean in the course of trouble shooting.

Peace

 

[MrShpongle]

So I threw a small amount of bleach (one capful) into the rez, let it mix for a few hours, then added a little CalMag. Not sure which one did it, but my pH problems stopped overnight! It sat right around 5.9-6.0 for the 5 days until I flushed the rez. At that time I also drained the entire feed manifold and rinsed it with a 5% bleach solution, just to be extra careful.

Let's see what happens going forward with the new batch of nutes.

 

[TheCleanGame]

---snip---

 

[zero244]

There are many variables when it comes to hydro and PH. If your having PH down problems reduce the strength of your nutrients, it wont stop them from lowering but they will be less likely to drop suddenly. To bring the PH back up add plain 7.0 water. I believe most people who do hydro try to grow there plants in overdrive and make the nutes too strong. The plant then uses more water than nutes causing the PH to drop. If you have a big res the effects of PH fluctuation is less rapid, but most of us dont have huge reses.