My pH keeps going back up to 8

ReLiK

Well-Known Member
ok so i got a hydroponic system and my pH is at 8 i added 10 mL of pH down to 20 gallon reservoir once. checked it next day its still at 8. did it again and now its still at 8... so what can i do guys :roll::roll:
 

T813308004

Well-Known Member
I would say keep adding it for a few more days and maybe it will go back up but eventually it should stay down because it will change the pH of the plant's roots and moisture so the plant doesn't add to the pH to bring it back up to 8.
 

jpalms27

Well-Known Member
what kind of meter do you have? i would recomend a trimeter since they have the probe with a cord. what you do is leave your meter plugged in and keep the ph and ppm probe in the resivoir and keep on checking it and every time you notice it the ph goes up bring it back down so your plants dont hit 8.0 and get stressed out...
 

Abnjm

Well-Known Member
ok so i got a hydroponic system and my pH is at 8 i added 10 mL of pH down to 20 gallon reservoir once. checked it next day its still at 8. did it again and now its still at 8... so what can i do guys :roll::roll:
When I mix my nutes, I need 20ml of pH down to lower the pH in a 10 gallon res by 0.4pH. I use the General Hydroponics pH down . With a 20 gallon res, at 10ml pH down, I would say you are going a little light on the pH reduction.

Where is your pH after you have added the pH down and it has been mixed? That is, before it mixes with the roots.

Good luck with your grow!
 

ReLiK

Well-Known Member
i use the cheap test, where u fill the bottle with water from the res and add drops to see the color. after adding the pH down it has gone down to 7 but always goes back up to 8 the next day. im gonna flush the reservoir soon and add more pH down this time n see what happens.

one more question, should i pH the reservoir first or add nutes first? thx in advance
 

Picasso345

Well-Known Member
Only two options. Bad meter, or in your case test strips, or some type of gunk growing in your res. Take your pick.

Getting ph correct is the last thing you do. Your plants couldn't give a shit what your water's ph is. They only care about what you give them. So that means PH after you add nutes.
 
get litmus paper...these are the most accurate
or a diggie pH

either the readings are wrong...or your plants are eating a crap load of nutes and making the pH bounce that high (i highly doubt this scenario).

keep your pH at 5.8 man...im surprised your not seeing big problems with a pH of 8 for three days
 

Abnjm

Well-Known Member
i use the cheap test, where u fill the bottle with water from the res and add drops to see the color. after adding the pH down it has gone down to 7 but always goes back up to 8 the next day. im gonna flush the reservoir soon and add more pH down this time n see what happens.

one more question, should i pH the reservoir first or add nutes first? thx in advance
OK. You must remember that I am on my first grow, and there are plenty of guys out there with more knowledge and experience than me.....

That being said, I would HIGHLY recommend getting a good pH and EC meter if you plan on going the hydro route. I paid less than $200.00 for both of mine. I understand you may be on a budget, but you really need to know these parameters to maximize your grow.

Anyways, working with what you have, I always mix my nutes in a separate container prior to putting them in the res. It's my Saturday morning thing.....cup of coffee and a smoke and I'm ready to go. I fill the water the night before and let it sit. First thing Saturday morning I add nutes according to the GH Nutrient calculator, mix them up and let them sit a couple of hours. I come back and check pH and EC. EC should be very close to plan if you measure your nutes carefully. After checking the pH I add the required amount of pH down, mix and let it sit for a couple of hours. I come back to re-check and add additional pH down if needed. I take copious notes on every batch I mix, and that allows me to know pretty accuately how much pH down I'll need to drop the pH in a 10 gallon res.

I let the batch sit overnight and check first thing Sunday morning and adjust as needed. (Rarely needed) After dumping the existing res, I give the container and the pumps a good scrubdown. I then refill and flood to make sure all the connections are tight.

When I was having problems with my pH rising, I would add 20 ml of H2O2 (35%) to the res every other day, and that fixed it. I wasn't very aggressive, as I believe you can mix the 35% at 1.7ml per liter while using non-organic nutes.

To wrap this babble-a-thon up, get the good analyzers if possible, add pH down after you've introduced your nutes, and add H2O2 if you think you may have some critter issues in the roots.

Good luck with your grow!
 

ReLiK

Well-Known Member
hmm well i cant afford a better pH tester atm but could it be im using tap water?? i have a 20 gallon res so.. i dont think i want to buy alot of distilled water or something.
 

Abnjm

Well-Known Member
hmm well i cant afford a better pH tester atm but could it be im using tap water?? i have a 20 gallon res so.. i dont think i want to buy alot of distilled water or something.
I have very hard and high pH tap water, (EC 0.8 / 400ppm @ 8.3pH) so when my nute levels were low, I mixed half tap water and half distilled in every batch. DW at Walmart is like $0.60 a gallon, and I'm sure you could find cheaper DW elsewhere. I have noticed that since I've gone to 100% tap water my pH levels are more stable.......

I don't think there is any more I can say to help you my friend.....

Maybe someone else will come along with other ideas for you.

Good luck.
 

ReLiK

Well-Known Member
ok so i change my reservoir pHed the water and it was at 8. added nutes it dropped to 7. then added pH down n dropped it to six. checked the next day its back at 8... and now i added 20 mL pH down. yesterday i added only 10. hmm :roll::roll::roll:
 

ReLiK

Well-Known Member
yes i scrubbed it really good. no i do not use h2o2. and im using Top Fin pH decrease got it from pet smart. its for freshwater.
 

VTECommie

Member
Sorry to bring it back, but I am having this same problem. Anyone have more info on "gunk in the res" I have a feeling that is my problem. I use a Hanna PH meter and have a GH test indicator as backup. As soon as I add ph down or up itll change for about a minute but it always levels back at 7. I do not use H2O2, add CO2, grow aero, change nutes every 10 days and have never seen this problem before. Any info would be great
 

VTECommie

Member
I think it is some bad bacteria growing. I cant use H202 because I run a number of organic compounds in my ressy. I am going to try adding some beneficial bacteria and an airstone
 
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