Life without PH Down

I run drain to waste with coco. I have a standard 40 gallon reservoir and I don't use ph down anymore. This is my fourth grow without ph down.

How do I do this? I'm using a resin provided to me by an organic chemist. The first time I mix my reservoir in a clean tank I throw in about 5 scoops of resin and then turn on a secondary pump to circulate the water around the tank causing the resin to work a bit quicker. The PH drops to around 5.8 where I like it. After I have run through the tank, I refill and repeat the process. The resin is heavier than water and sits on the bottom of the tank like a coarse sand. If it looks like it is starting to weaken and ph is higher than I would like, I throw in another scoop or two. I use my meter infrequently and could probably live without it.

It's not an idiot proofed system. Once I did add way too much and the ph dropped down to around 5. Had to scoop some out of the bottom of the tank and add more water.

I suspect the resin would be more useful to someone who was using a recirculating system with smaller reservoir who was having problems keeping their ph down.

If you are doing a small recirculating or deepwater grow and would like samples to test I can provide some. I just want to know what experiences you have from it.
You will need to be able to recirculate the water in your reservoir to make it work. Bubbles or a secondary pump can accomplish this. Ideally I would prefer people who
have smaller reservoirs of say 30 gallons or less since I have limited test material.

Its still basically a ph down. Lots of ways to skin a cat.

No, ph down is just a one way ticket down and not selective. When you add ph down, you're just adding more ions to the solution.

This material will selectively add or remove ions to keep the solution at a set stable level. If you add fresh water, it will release ions until the ph drops. If the plants suck up water concentrating nutrients it will pull in ions keeping the ph from dropping below the setpoint.

http://hortsci.ashspublications.org/content/28/10/981.full.pdf
This will explain it!

Yep, that explains it.

If I didn't have to give you my address I'd be all about it.

This is pointless... Just use nitric acid or phosphoric acid based pH down, preferably nitric acid.

Who with experience has pH swinging issues?

I have 550ppm tap water, put in the same amount of nitric acid based pH down every time, mix the same amount of nutrients every single time, and get the same pH every single time and it goes up slightly until i change the tank, every single time.

If your pH is swinging, it's either because calcium phosphate is precipitating out of the solution, or the plant is eating certain nutrients faster than others causing H+ or OH- to accumulate faster by the roots. This means if your pH in a hydro system is radically changing, it's either because you're doing it wrong or because you're doing it wrong.

If your pH is swinging, it's either because calcium phosphate is precipitating out of the solution, or the plant is eating certain nutrients faster than others causing H+ or OH- to accumulate faster by the roots. This means if your pH in a hydro system is radically changing, it's either because you're doing it wrong or because you're doing it wrong.​

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I know when I first started ph was my biggest issue trying to keep it stable, as church says once you get a handle on it, it is pretty easy to keep it constant or real close. Mine drops a bit over res changes but not drastic. But thanks for the thread it is an interesting concept! And it may be useful for some people IMO, not churches though lol.

So, to summarize your argument. You do it one way and it works so everyone should do it that way.

Perhaps you should wander off to the CFL forum and tell them they should switch to HID because that's what you use.

Just because something works for you doesn't mean that is the only way to do it. There are a lot of different ways of growing.

You may note that there are many threads on ph issues. Some growing methods are more apt to generate ph shifts. And some
people like me, would rather just dump in a half cup of resin and not worry about ph for the rest of the grow.

Until you come up with some strange growth fro smoking resin induced buds. Lol, just playing.

Basically, yes that's my argument. If you're running hydro, you should use nitric or phosphoric acid based pH down, maybe sulfuric if low on sulfates in the solution.

By suggesting that I run off into the CFL forum, are you implying that you think nitric acid is indeed a better pH down than some blob of resin, because HPS > cfl for flowering any day.

Something working for me isn't the only reason everyone else should do what I do.

You made it pretty clear that you still had problems keeping pH correct even with your mystery resin by adding too much. How is that even an advantage?

And now you're making the claim that you can just add some and leave it for the rest of the grow? You never change out your tank for the whole grow? I only have to pH once when I change out the tank to deal with my hard water, and then pH stays the same until the next tank change. When using RO water, I need 0 pH down, period.

Like I said, if your pH is swinging, it's either because you're precipitating calcium phosphate, or you have the wrong balance of nutrients for your plants. If you have to keep adding nitric acid, it's because your plant is eating anions faster than cations, so feed it anions with free radicals to balance the cations with free radicals!

Do you people realize that when you add pH down, you're feeding the plant? Why would you want to feed it some random blob? This isn't soil. We feed our plants nitrates and phosphates in the hydro world, not resinates.

Then... how much does this resin cost in comparison to nitric acid? What is the purpose of the switch? It sounds like you need to add the exact amount of resin to get the pH right. You said it's not just a downward ticket, it goes up too, but then said you added too much and went too low. That sounds like a major contradiction. How is that better?

Kervork said:

So, to summarize your argument. You do it one way and it works so everyone should do it that way.

Perhaps you should wander off to the CFL forum and tell them they should switch to HID because that's what you use.

Just because something works for you doesn't mean that is the only way to do it. There are a lot of different ways of growing.

You may note that there are many threads on ph issues. Some growing methods are more apt to generate ph shifts. And some
people like me, would rather just dump in a half cup of resin and not worry about ph for the rest of the grow.

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Were you trying to use lemon juice as pH down before or something? Give someone a shovel and they'll insist their stick with a sharp rock on it is better.

Kervork said:

So, to summarize your argument. You do it one way and it works so everyone should do it that way.

Perhaps you should wander off to the CFL forum and tell them they should switch to HID because that's what you use.

Just because something works for you doesn't mean that is the only way to do it. There are a lot of different ways of growing.

You may note that there are many threads on ph issues. Some growing methods are more apt to generate ph shifts. And some
people like me, would rather just dump in a half cup of resin and not worry about ph for the rest of the grow.

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Hey you tweaked my interest lol. And your right there are a lot of people who dont want to try new (actually kinda old lol) methods. I am shutting down the indoor for the summer but will read up on the stuff. I think its readily available in my area as I googled a couple of places. It would be nice to just add water when topping up and not fuck with the up or down in between refills. Again thanks for the thread.

If you get carried away and you add three or four times as much resin as needed, yes it will drop the ph very low. The varient which uses calmag doesn't seem to do this. If I took careful notes I would no doubt know exactly how much to add. I've been working with several different formulations over time, they don't all act the same. They all have grown successfull crops without the use of any ph down.

Given what I have paid for ph meters and ph down, using resin would have been cheaper. I figure its probably about 2 bucks a grow, maybe 5 or 7 scoops.

Since I've been using the resin my ph hasn't been swinging. I don't recall saying it was swinging before either. Many people do have ph that swings. I'll bet if you tried to grow deepwater in gallon pots like someone I know your ph would be all over the place. Why are you obsessed with ph swings to begin with? Is there something you're not telling us?

You seem intent on tryign to tell me that what I'm doing doesn't work. I've done it, it works. I'm happy with it. And the calmag formulation does feed the plants, calcium and magnesium.

My plants are quite capable of living on the nutrients I give them. That's what the nutrients are for. I don't need to use ph down to feed my plants.

So what the fuck is your point again? That everyone should use liquid acid because thats the way it always has been and it can never be improved on?
Get a fucking life. People do things differently and those ways can also work. You're accusing me of lying and claiming what I'm doing can't work all
the while I have been doing it. I have the results to prove it. I'm happy with it, I'm not going back to using acid.

The history of hydroponics has shown constant additions of new technologies. No doubt each time one was developed someone sat in the corner
whining about how it will kill the plants and start fires or cause hermaphrodites.

Kervork said:

Given what I have paid for ph meters and ph down, using resin would have been cheaper. I figure its probably about 2 bucks a grow, maybe 5 or 7 scoops.

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pH down is food. It's either nitrates or phosphates, which you need anyway. Without hard water, pH down isn't necessary anyway if you have the right nutrient mix. The only reason I add pH down at all is because I have extremely hard water (550ppm). It takes exactly 60mL of the nitric acid based pH down I'm using to neutralize that much CaCO3 in 4 gallons, and then when I add my nutrient mix, the pH goes to around 5.5 and rises very slowly.

Kervork said:

You seem intent on tryign to tell me that what I'm doing doesn't work. I've done it, it works. I'm happy with it. And the calmag formulation does feed the plants, calcium and magnesium

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I'm not saying it doesn't work, I'm just saying it's sort of pointless. If your pH is swinging and nothing is precipitating out, it's telling you something. If pH is going down, it's telling you it's eating cations faster than anions and if it's going up, it's telling you it's eating anions faster than cations. For example, if pH is going up, it's eating phosphates and/or nitrates faster than it's eating potassium, calcium, or magnesium. Not sure what you're getting at with calmag product.

Kervork said:

So what the fuck is your point again? That everyone should use liquid acid because thats the way it always has been and it can never be improved on?

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Yes, that's my point. When it comes to anions, plants want nitrates, phosphates, and sulphates... using the mystery resin makes no sense to me. With low ppm tap, pH down is pointless unless you have the wrong NPK Ca Mg ratios for what the plant demands, and adding pH down is like saying you're sorry for screwing that up and making amends by giving it the element you were holding back on.

Personally, I think this is pretty damned elegant. cn

This is pointless

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Give someone a shovel and they'll insist their stick with a sharp rock on it is better.

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Actually church, I dont think he was saying it was better, my take was he was trying to find out if it was better. I will read up on it before I decide wether its a good thing or a bad thing re:toxicity, etc. What little I have read is quite interesting actually. If I was to ever get enough stash in the box to actually risk a grow to testing (girlfriend smokes a ton ), I would try a few different things lol. For now I will stick to the proven technologies to be safe which is kind of unfortunate I think.

I dont get the cost thing. $2 per harvest for ph adjuster is a lot. I spend $40 per year(2 gallon) on ph down for close to 300 plants and around 2500 gal of nute mix. I check ph maybe every 3-5 days and it takes less than 10 mins to measure and/or adjust 4-5 res's(200-250gal). Not a lot of time at all.

Yes, playing with ph down isn't that hard. I have three ph meters at $35 a pop sitting on my counter. One of them works. The other two were destroyed various ways. Don't forget the cost of 7 and 10 calibration fluid and time spent calibrating your meter. I won't argue that ph down is cheap. Dropping meters in the reservoir gets expensive. Killing plants because you're a indicator solution using noob gets expensive too.

My water is around 200ppm. When I mix a reservoir the ph winds up at about 6.8. You're trying to tell me that although I mixed nutrients exactly according to the manufacturer instructions that I somehow screwed up because my ph is at 6.8. I think that 500ppm water you're using must be full of lead. I don't recall my ph magically winding up at 5.8 when I was briefly using RO water either.

Anyone out there with tap water at 7.8 who gets it down to 5.8 without adding ph down?

Anyway, this is out of the linked report

This study demonstrated that root-zone pH stabilization was necessary for solid-matrix hydroponics to optimize seed yield rates of
dwarf, rapid-cycling brassica. The two pH control strategies tested, MES buffer and cat-ion-exchange resin beads, were successful in
stabilizing pH fluctuations within the rhizos-phere of a low ion-exchange substrate. In general, both experimental treatments doubled
crop yield rates over that of unbuffered ma-trix-based hydroponic systems. Even a small amount of ion-exchange (i.e., buffer) capacity
may significantly enhance the yield of crops grown in hydroponic systems using a solid matrix for physical root support.

My next test may be mixing resin directly in the coco.