Is using pH down daily bad for plants?

Simple question, but I've never gotten a simple answer.

I am using a Ebb/Flow system with a 5 gallon Home Depot bucket as a reservoir (I have taped it up with aluminum tape to make it as light proof as I can). I flood the tray for 15 minutes (smallest increment my timer can do) every 4 hours.

Every single day when I come home from work, I test the solution and it always rises to about 6.2 - 6.3. I then pH it back down to 5.5 - 5.8.

A. Any ideas WTF is making the pH jump up daily? I have tried everything I can think of (light-proofing the res, adding H2O2, etc.) with no luck. I have gone almost insane trying to deal with this.

B. Is the adding of pH down daily hurting my plants? Since I started trying to grow, my plants have never looked healthy. I am unsure of whether it's the high pH at the end of the day that is hurting it, or it's the pH down.

I have tried to use the search function, Googling, asking hydro shop personnel. I just cannot get an answer that helps me.

What do you guys think? Thanks in advance!

6.2-6.3 is very aceptable imo, my nutes are designed for 5.8-6.2 but they hover right at 6.3 I fought them for weeks with no luck and now i just leave them at 6.3 and it stays there good. my plant seems to like the # so thats where it stays now. i did notice that when i ph down every day my plant looked a little off color so i think too much phos acid is not good for hydro.give it a shot at 6.2-6.3 and also try checking your ph in the morning when your tanks are cooler. you might get a lower number then.good luck

I personally notice that if i ph down everyday the plants dont like it. I now just sit back and watch it. If it raises to 6.3 or 6.5 i leave it. Then when i add my water to the res and pull it down to 5.8 or so. OK enough ramblin what im saying is that I find it bad to adjust your plants all the time and just relax. It'll be all right.

Everyone is so set on keeping it at the "perfect ph", there isnt one. Roseman says it all best.

Ringo

Good thread, great info sixstring2112.

Any help on my post will be great full. Either of you.

https://www.rollitup.org/indoor-growing/314952-1st-time-using-flood-drain.html

Thanks.

Is light hitting the water in the table? Do you see any algae at all? If so, try some H202 (hydrogen peroxide), you may have some buildup on the roots.
How often are you changing your resevoir?
6.3 isn't out of range for hydro. I like 6.0 but I dont bat an eye if it goes up to 6.3.
What kind of water are you using? RO, Tap?

Also what is your res temp when you are checking your ph.

@ sixstring: I tried leaving my pH @ 6.3 and the leaves of my plants are crazy twisted. I am not sure it's because of the pH, but when I try looking up what causes twisted leaves it looks like Zinc def which is caused by pH being too high.

@ Sgt Pepper: So you're water is low enough in pH naturally to bring down your soln's pH or you pH your water first before adding?

@ reefcouple: There is no algae on the table, but I was worried that the amount of time that the light hits the soln while flooding was causing a problem. There is a bit of algae in a pot that is made of a clear water bottle. I was considering getting a digital timer with smaller increments, but don't really have the funds to spend unless it'll make a difference. What do you think?

@ sixstring: My soln temp is @ 24.5 deg C during reading.

I will not adjust my soln tonight and see what happens. Fingers crossed.

dR. HerbLove said:

@ sixstring: I tried leaving my pH @ 6.3 and the leaves of my plants are crazy twisted. I am not sure it's because of the pH, but when I try looking up what causes twisted leaves it looks like Zinc def which is caused by pH being too high.

@ Sgt Pepper: So you're water is low enough in pH naturally to bring down your soln's pH or you pH your water first before adding?

@ reefcouple: There is no algae on the table, but I was worried that the amount of time that the light hits the soln while flooding was causing a problem. There is a bit of algae in a pot that is made of a clear water bottle. I was considering getting a digital timer with smaller increments, but don't really have the funds to spend unless it'll make a difference. What do you think?

@ sixstring: My soln temp is @ 24.5 deg C during reading.

I will not adjust my soln tonight and see what happens. Fingers crossed.

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I heard a long time ago, long long time ago, that you should age water three days and then do the ph down or up. Why don't you try it and lets us know.
I believe I read it on a gardening magazine.

24.5 is getiing up there. that might be your problem.I check my res in the morning @ about 18c and ph is usually around 5.9-6.1 then i'll check at night and it will be 6.2-6.4 with my res @ 20c-21c .I had res problems when i first started doing the hydro thing and i believe they were all from high res temps, mine was always around 23-25c. can you get a fan on the res,i use a small computer fan on mine. or you can put your res in another res or bucket and cool it with ice or cold water from a garden hose. i bet most of your problems will go away if you get them down around 19-21c, but you might try some h2o2 now in your res to clean out the bad stuff. i use 10ml for 3 gallons of res but you can use up to3 ml per liter.I am interested in your nutes, what all you use. if you are using organics,nitrozime or hydrozime h2o2 will not help.when i was having my problems i was using too much bullshit at once. I dumped my res and started over with just ionic grow @ 800 ppm and h202 @10 ml for 3 gallons.roots looked better in 2 days and ph problems were gone. before i dumped my res i did a flush with florakleen for 3 hours (bottle said 2 hours)good luck

If you let the water sit out a day or two my tap water is 5.8. 7.4 before. I have a ph51 ph pen from millwaukee and it adjust to temps auto. Very nice.

H2o2 will help. Also do you have any airstones in your res? that would help.

Also to sixstring. I also had a problem at first, using to much stuff at once. i cut everything out except the boost and grow. They are just as happy and I have no problems with the res. anymore. Im 4wks in flowering and just brought in awesome blossom and sugar daddy. Sugar Daddy was the ph problem culprit im pretty sure in the start.

Pete Best

Hey Guys,

So a few things I forgot to mention in my last post:

1. I am using RO water purchased from a local water shop.

2. I am using GH Flora series nutes, which is synthetic and shouldn't be a problem with H2O2.

3. I hit my res with Mad Farmer H2O2 every other day. Doesn't effect pH movement at all.

4. I blast my reservoir with an airstone 24/7.

5. I'm using this Hanna Combo pH meter (http://hannainst.com/usa/prods2.cfm?id=002003&ProdCode=HI 98129).


I just checked my reservoir. The soln is reading 6.4 @ 21 deg. It looks like the plants really aren't liking it. They are in sleep more right now, so I will check back tonight. Thanks for all your input guys. I really appreciate it!

How do you mix your res water? Do you ph down first(what is the starting ph of the ro water?) or add your nutes?

I used ro water at first then switched to tap water as it didn't make a difference to the plants, but the ph is really stable, but it has to sit out.

I use technaflora and it has ph buffer as in it keeps it what its at. Just checked the res for the first time in a week (since I feed the gal) it went from 5.8 to 6.3. Its also more stable since i stopped changing the res every week to every 2 weeks, no problems yet. 12gls of water in a 16gl tote, 2 gals.

Are they any pics of the setup? Maybe we can spot something. How big is your res also.

Peace
John

Sgt Pepper said:

How do you mix your res water? Do you ph down first(what is the starting ph of the ro water?) or add your nutes?

I used ro water at first then switched to tap water as it didn't make a difference to the plants, but the ph is really stable, but it has to sit out.

I use technaflora and it has ph buffer as in it keeps it what its at. Just checked the res for the first time in a week (since I feed the gal) it went from 5.8 to 6.3. Its also more stable since i stopped changing the res every week to every 2 weeks, no problems yet. 12gls of water in a 16gl tote, 2 gals.

Are they any pics of the setup? Maybe we can spot something. How big is your res also.

Peace
John

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Well I usually just fill up the reservoir then add Flora Micro, then Flora Gro and Flora Bloom.

Followed up with a good mixing then H2O2. Then I pH it to 5.5.

The tap water at my place comes out of the faucet at about 500 ppm. So I don't think it'll work.

Those Technaflora nutes sound really interesting. Whatever I can do to control the pH I will try.

I haven't adjusted the pH in a couple of days and last I check this morning the pH was @ 6.5. Yikes! I think my plants were hurting.

I am using a 5 gallon Home Depot bucket as a res. I tried wrapping it up with aluminum tape to try to lightproof it.

I will definitely take some pix when I get home. Thanks for all your help!

I use ro water from my own ro unit. I store my water in 44 gallon garbage cans and have an aquarium heater and air stone on them all the time. My unit fills both storage cans in 4 days or so and I change out my buckets once a week. I found that having my water aged, aerated and temped to my rez temps it makes it easier with less hassles and variables. I use the flora series as well and it buffers my water to 5.5 every time.

There is nothing wrong with your system. Your plants are simply taking up large amounts of nitrate which causes the plants to release carbonate ions, with the end result being a rise in pH. While GH does have a fair load of ammonium, about 6% of the total nitrogen, this is not taken up well at high temps. You should NOT allow your pH to stay above 5.8 as inert medium hydroponic nutrient availability sucks at a pH above 5.8. The twisting and such deformed growth is a result of phophorus deficiency caused by a high pH. The chief component of pH down is phosphoric acid. It is not only dropping your pH down to where it belongs but is providing the phosphorus needed. Many people growing with GH two part often have problems with phosphorus defficiency if growing at high temps.

RO water made from tap water that was hard water will have a low pH (acidic) as the membrane removes the calcium or magnesium from the carbonate hardness but that leaves a butt load of carbonate which becomes carbonic acid. With aeration this is outgassed as CO2.

Freshly made RO water should not have a high pH if the membrane is working. A high pH usually acocmpanies a high TDS which means the RO membrane would need replacment. A bad RO membrane allows passage of alkalinity (carbonate hardness) which causes a high pH.

fatman7574 said:

There is nothing wrong with your system. Your plants are simply taking up large amounts of nitrate which causes the plants to release carbonate ions, with the end result being a rise in pH. While GH does have a fair load of ammonium, about 6% of the total nitrogen, this is not taken up well at high temps. You should NOT allow your pH to stay above 5.8 as inert medium hydroponic nutrient availability sucks at a pH above 5.8. The twisting and such deformed growth is a result of phophorus deficiency caused by a high pH. The chief component of pH down is phosphoric acid. It is not only dropping your pH down to where it belongs but is providing the phosphorus needed. Many people growing with GH two part often have problems with phosphorus defficiency if growing at high temps.

RO water made from tap water that was hard water will have a low pH (acidic) as the membrane removes the calcium or magnesium from the carbonate hardness but that leaves a butt load of carbonate which becomes carbonic acid. With aeration this is outgassed as CO2.

Freshly made RO water should not have a high pH if the membrane is working. A high pH usually acocmpanies a high TDS which means the RO membrane would need replacment. A bad RO membrane allows passage of alkalinity (carbonate hardness) which causes a high pH.

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Great explanation! I did have one question though. How is it that other successful growers do not seem to have this problem? From the grow journals I've read through it seems like people usually just adjust the pH during reservoir changes. Is it just a matter of the nute brand?

As for my RO water, I purchase it from a water shop and it comes out to about 7 pre-soln.

Thanks for your help.

Here are some pictures of my setup:







I just changed the res and now it's at a 5.7. I added some H2O2. We'll see how long it last.

Many growers tell tall tales. A nutrient resrvopirs pH is going to be controlled by the uptake of nitrate and ammonium. Simple as that. Retailed mj nutrients are formulated for average growing conditions and an average pot strain. I have no idea what average grow systems or conditions really are, nor do I know what an average pot strain is. Apparently the mj nutrient manafacturers are just special and have that knowledge.

Larger reservoirs and more frequently changed reservoirs will have less noticeable pH changes, but will still have changes. Any plant that has a large demand for nitrogen that is supplied with that nitrogen will cause a rise or decline in pH unless the dynamics of that system and the strain that is being grown just happens to be satisfied by your average nutrient formulas nitrate to ammonium ratio. That is seldom the case. Most alledgedly sucessful growers are nearly always bordering on underfeeding their plants as far as nitrogen so of course the effect is less pH wise. If the plants are growing slowly the effects are less as the nitrogen uptake is less. A mj plant growing hydroponically at its optimum rate really needs a pH controller as the pH change will be so severe. Few "successful" growers grow that sucessfully. There are also many "successful" growers who allow large swings in their nutrient pH. I think you would have a hard time finding any large sace le commercial growers who allow a swing in pH outside the optimal range of 5.6 to 5.8. Most commercial growers install auto water top off systems, pH controllers and EC controllers if they grow with recirculatory reservoir systems. They pay them selves off in one grow if it is a sizable grow. The best alternative is simply growing with a drain to waste system. However it takes a bit of experience to set up and manage a drain to waste system both sucessfully and economically. Usually it is people with extremely large hydro systems or high pressure aero or air atomized ssytem that grow drain to waste. It also helps a great deal if you mix your own fertilizers as that reduces the cost usually by a factor of 10 to 20.

http://cgi.ebay.com/Omega-PHCN-37-Microprocessor-based-pH-Controller_W0QQitemZ190382865101QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2c53b3facd

Retail site:

http://www.omega.com/ppt/pptsc.asp?ref=PHCN37

This pH controller uses a standard pH probes as used on nearly all pH meters. It retails for about $400. Simply use it with two cheap little plastic 110volt solenoid valves. Gravity feed the valves and gravity feed from the valves to your reservoir.

http://shop.ebay.com/i.html?_nkw=plastic+solenoid+valves&_sacat=0&_trksid=p3286.m270.l1313&_odkw=pinch+valves&_osacat=0&bkBtn=

About 2.5 to 5 gallons per plant with large plants is about right for a reservoir size.

5 gal Rez? Try goin 15-20 gallon Rez and your ph won't jump around so much buddy

kabona said:

5 gal Rez? Try goin 15-20 gallon Rez and your ph won't jump around so much buddy

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Hi i noticed in ur pictures you are using glass jars and clear palatic containers??? NOt really a good idea greeen pots are at the hardware store for 50 cents each go buy some . Iam only assuming that some light is deffently seeping through the sides of your containers. For 5 dollars you will have a potential elimanated