DWC PH issues: Ph dropping like a rock - Please help

His feed is going up cause the pH is out of range and the plant is still drinking water and because the pH is out of range feed isnt being taken in and that results in a ppm rise.

I used to be a lazy gardener and would start off at 1.2-1.3EC it would drop immediately cause it was hungry and cause the pH to rise since nutes are acidic and if you remove an acid from the solution the alkalinity will increase and then my pH would be out of range and then id get an increase as the plant drank water.

Im not a pro but this is my understanding.

John1961 said:

Although I agree with you that all of these res changes might have been a bit much, I thought it was a better option than continuing to use water that had so much PH-Up added to it already. I figured that starting over with fresh water would be less stressful.

Click to expand...

If the ph was low then there wasn't much ph/up to worry about, if the ppm was high then yes I'd probably dump it...actually I'm cheap so I'd probably just add straight water back and adjust the ph again. Seriously though...I had this issue and it drove me bananas and I almost ditched hydro and went back to soil and hempy's but a few guys here had me try the proteck instead of ph/up and it worked as a great buffer and gave the plants silica which made them more resilient to pests and mold etc. It may or may not work for you. I also personally found dyna-gro products easier to work with in this regard but that's just my opinion. Good luck friend.

@taproot - Thanks for the advice. I've been reading a lot about ProTeck and plan to hit my local hydro shop on Saturday to pick some up. I plan to ask them about my PH issues to see what advice they might have to offer.

In your experience, did the ProTek keep the PH stable for a longer period of time? Since switching to tap water, my PH seems to stay more stable throughout the day. But when I was using the RO water, it seemed my PH would swing wildly.

John1961 said:

@taproot - Thanks for the advice. I've been reading a lot about ProTeck and pan to hit my local hydro shop on Saturday to pick some up. I plan to ask them about my PH issues to see what advice they might have to offer.

In your experience, did the ProTek keep the PH stable for a longer period of time? Since switching to tap water, my PH seems to stay more stable throughout the day. But when I was using the RO water, it seemed my PH would swing wildly.

Click to expand...

Well, yes like I said I never dumped my tanks for the entire grow except the last two weeks of flower which they got straight water. Plus the silica made the stems much more stronger and the plant more resilient overall. Another thing about ph that I read and found to be true is the fact that the larger the rez the more stable the ph is. I was using storage totes you can get at walmart...I think they were around 10 gallons each. Stick to tap water and save your money...as long as you're not on a well your water is probably just fine.

Well, my excitement was short-lived. Using tap water in my reservoir, my PH dropped from 5.8 yesterday afternoon (It was 6.1 in the morning) to 5.2 this morning. She drank a bit less than a quart overnight. PPMs dropped slightly to 570 ppm.

So I topped off the reservoir with some nutrient water and added 2ml of PH-Up to the reservoir. I can only imagine that adding PH-Up to a reservoir that already has a bunch of PH-Down swimming in there cannot be good for the plant.

This shit sucks.

Man you are overreacting. Relax. Ive added pH down, over-corrected, then added pH up and was fine.

Use lucas formula, start at 6.1 and let it drop. If it goes to 5.1 who cares. Provided you dont have root rot just play the pH chasing game. Everyone does it with bubble buckets, its just usually the other way around. Mine would raise 5.5 to 6.3 daily.

@firsttimeARE - Thanks, you're right, I need to ease back a bit. I'm just finding this so fricken frustrating that I cannot determine a cause for the nightly, and IMO, massive PH drops in my reservoir.

I think you are under feeding TBH. Use lucas at 700ppm and read up on osmotic pressure and how plants exchange nutrients from the nutrient solution to the root zone.

I use 600ppm but my water is only 80. So thats 520ppm of nutes. With 220ppm of water at 590ppm thats only 370ppm of nutes. As i said above, thats not enough.

John1961 said:

@firsttimeARE - Thanks, you're right, I need to ease back a bit. I'm just finding this so fricken frustrating that I cannot determine a cause for the nightly, and IMO, massive PH drops in my reservoir.

Click to expand...

are you using max dose of hydroguard?

i'm wondering if you have just a bit of root rot going on. one thing you can do is fill up something like a pitcher with your nute solution and top feed your plant so you are getting the hydroguard way up into the root ball.

firsttimeARE said:

I think you are under feeding TBH. Use lucas at 700ppm and read up on osmotic pressure and how plants exchange nutrients from the nutrient solution to the root zone.

I use 600ppm but my water is only 80. So thats 520ppm of nutes. With 220ppm of water at 590ppm thats only 370ppm of nutes. As i said above, thats not enough.

Click to expand...

for a plant his size, i think the ppm should be dropping way more than 10 per day and it should be drinking way more than a quart. i have 2 half the size that are drinking a gallon a day each.

rkymtnman said:

are you using max dose of hydroguard?

Click to expand...

Yes, sir. I use 2ml for every gallon of water, whether I'm doing a reservoir change or just topping off.

rkymtnman said:

for a plant his size, i think the ppm should be dropping way more than 10 per day and it should be drinking way more than a quart. i have 2 half the size that are drinking a gallon a day each.

Click to expand...

And that tells me the plant is leaching nutrients from the root zone into the water due to the low concentrations in the water vs whats in the roots. If the osmotic pressure in the res was greater (higher feed) the roots would absorb the nutrients.

This could be because of bad ratios(too much of nutrients it doesnt need a lot of vs ones it needs lots of) or underfeeding. I think its underfeeding. But I didnt run his feed thru a calculator so who knows, could be a bit of both.

Plant cells transport thru their membrane from areas of high pressure to low. Similar to how the stomata on the plants leaves open or close in response to either high or low VPD.

John1961 said:

Yes, sir. I use 2ml for every gallon of water, whether I'm doing a reservoir change or just topping off.

Click to expand...

is it a fairly new bottle? hasn't been open for a long time?

firsttimeARE said:

And that tells me the plant is leaching nutrients from the root zone into the water due to the low concentrations in the water vs whats in the roots. If the osmotic pressure in the res was greater (higher feed) the roots would absorb the nutrients.

This could be because of bad ratios(too much of nutrients it doesnt need a lot of vs ones it needs lots of) or underfeeding. I think its underfeeding. But I didnt run his feed thru a calculator so who knows, could be a bit of both.

Click to expand...

this one stumped me for sure.

if my EC was too low, it would drop 50 pts a day or more. then i'd bump up my EC until it just barely was dropping.

rkymtnman said:

is it a fairly new bottle? hasn't been open for a long time?

Click to expand...

@rkymtnman - Yes sir, all of my nutrients and supplements were purchased new in August when I started this DWC.

firsttimeARE said:

...the plant is leaching nutrients from the root zone into the water due to the low concentrations in the water vs whats in the roots. I think its underfeeding. But I didnt run his feed thru a calculator so who knows.

Click to expand...

@firsttimeARE - Can you tell me more about this calculator you mentioned? I've been reading a lot about the Lucas formula but have not tried it. My goal all along has been trying to figure out the cause of the large PH drops every night. Once I knew what was causing it, I could address it. As it feels now, I'm stabbing in the dark, changing this & and adjusting that in hopes of finding the problem. I'm hoping I'll eventually figure it out, but sheez!

rkymtnman said:

this one stumped me for sure.

if my EC was too low, it would drop 50 pts a day or more. then i'd bump up my EC until it just barely was dropping.

Click to expand...

EC low was because your plants were hungry and were eating a lot and your water level was dropping and pH rising. That says the root zone EC was lower than the solution EC so you get ion exchange into the roots removing acidic ions and leaving,more water which has a higher pH which is why the pH raised. Youd raise it and eventually,it maintained equillibrium.

His EC is raising with,minimal water level droppage and pH drops. To me that says the plant is leaking acidic nutrients into the res lowering the pH because the root zone,pressure is greater than the pressure around it(too low of nutrient solution). Ion exchange works from high to low pressures. He then reduced his feed even further which would eventually lead,to equillibrium but at the expense,of nutrient,deficiencies.

If he raised nutrients the plant would absorb the nutrients removing acidic,ions and the pH would raise as the EC drops.

John1961 said:

@rkymtnman - Yes sir, all of my nutrients and supplements were purchased new in August when I started this DWC.



@firsttimeARE - Can you tell me more about this calculator you mentioned? I've been reading a lot about the Lucas formula but have not tried it. My goal all along has been trying to figure out the cause of the large PH drops every night. Once I knew what was causing it, I could address it. As it feels now, I'm stabbing in the dark, changing this & and adjusting that in hopes of finding the problem. I'm hoping I'll eventually figure it out, but sheez!

Click to expand...

Hydrobuddy. Input what you are feeding is made of (% of the nutrients and their chemical name) and then adjusy the concentrations you are feeding at and,it will,give you a ratio. This is important as certain,nutrients act as a protagonist or an antagonist to other nutrients when they are beyond a certain,ratio. The chart is called Mulder's.

So to read that chart green arrows pointing to a nutrient B towards a nutrient C means nutrient B helps the absorption of nutrient C.

Relating to the chart Mn (Manganese) helps the absorption of K (Potassium) and since there is an arrow pointing from K to Mn, K helps Mn absorption.

Red means they act against. K, Ca, Mg is a common one. Lucas formula aims for a 4:2:1 ratio between the three. 4 parts K to 2 parts Ca to 1 part Mg

What do you have to lose? You tried decreasing feed and it didnt work, try increasing it a little.

I feed 1.0EC of straight nutrients (500ppm on my scale) for you water thats 1.4EC or 700ppm and most will say I underfeed, so you are more than likely underfeeding since your at 0.7EC of actual nutrients.

What brand meter are you using?

OK, so after my adjustments this morning and letting things stabilize, here is where I'm at as of now:

• Water volume: 5 gallons
• PH: 6.1
• PPM: 570 (.500 scale) (starting PPM of the tap water when I changed the res 2 days ago was 180 ppm)
• EC: 1.1
• Water temp: 67.2

@firsttimeARE - I am using new Blue Labs PH & PPM pen meters.