PH. Crashing and can't stop it..

  • Thread starter Waterlogged
  • Start date
  • Tagged users None
Waterlogged

Waterlogged

20
3
Hello, I am new to this form and this is my 1st post hoping I can get some answers. I have a 30 gallon reservoir using r/o water and I'm doing drain to waste. The big problem is my ph is dropping drastically just sitting in the reservoir circulating, it goes from 5.8 to 3.8 in 3 days and I can't figure out why, I am using nutrients at about 800 ppm, any advice would be appreciated, thank you in advance.
 
growsince79

growsince79

9,065
313
Hello, I am new to this form and this is my 1st post hoping I can get some answers. I have a 30 gallon reservoir using r/o water and I'm doing drain to waste. The big problem is my ph is dropping drastically just sitting in the reservoir circulating, it goes from 5.8 to 3.8 in 3 days and I can't figure out why, I am using nutrients at about 800 ppm, any advice would be appreciated, thank you in advance.
mix with tap water.
 
Waterlogged

Waterlogged

20
3
So I'm using botanicare products, and I ph to 5.8 and it goes to 4.0 within two days, doing drain to waste using r/o and about a gallon of city water to get the r/o to 80 ppm then add nutrients to 800, it just sits there circulating and drops every day fast. Hope I answered your questions, if ya need more details please ask and I will give them, I can not figure this out. Thank you for any input.
 
tobh

tobh

Supporter
4,194
263
So I'm using botanicare products, and I ph to 5.8 and it goes to 4.0 within two days, doing drain to waste using r/o and about a gallon of city water to get the r/o to 80 ppm then add nutrients to 800, it just sits there circulating and drops every day fast. Hope I answered your questions, if ya need more details please ask and I will give them, I can not figure this out. Thank you for any input.
how are you circulating the solution? venturi pump? submersible just sitting in the res? air pumps?

are you adding any other additives like silica?

One thing the Master himself, @Aqua Man recommended to me, when I switch to MSA from potassium silicate was to add 75ppm of pH up to the solution, then bring it back down to 6.5 and proceed with mixing the nutrients. What this does is adds a buffer. You have to have alkalinity in the solution otherwise the acid you use to get to the range you want will just run rampant.

Another potential cause of sudden, aggressive pH drops is bad bacteria taking hold, though I can't really see that being a problem in DTW so much as in a recirculating system.

So let's focus on your setup. Describe your system in as much detail as possible, and the process you follow for mixing nutrients along with any other additives.
 
Waterlogged

Waterlogged

20
3
Thank you for the replys, I am using just a submersible pump, I fill it with r/o first then tap water to i hit 75 ppm then I add cal mag then botanicare some liquid karma, floralishous and moab, then ph it to 5.8. two days later its at 4.0 just sitting in the res. Using 315's. Temp 70 humid 50, If ya need more info let me know please and thank you.
 
freezeland2

freezeland2

3,421
263
Thank you for the replys, I am using just a submersible pump, I fill it with r/o first then tap water to i hit 75 ppm then I add cal mag then botanicare some liquid karma, floralishous and moab, then ph it to 5.8. two days later its at 4.0 just sitting in the res. Using 315's. Temp 70 humid 50, If ya need more info let me know please and thank you.
Are you using ph up to bring it back up in range?
 
DrStadanko

DrStadanko

37
18
So I'm using botanicare products, and I ph to 5.8 and it goes to 4.0 within two days, doing drain to waste using r/o and about a gallon of city water to get the r/o to 80 ppm then add nutrients to 800, it just sits there circulating and drops every day fast. Hope I answered your questions, if ya need more details please ask and I will give them, I can not figure this out. Thank you for any input.
Make sure your Reservoir is covered
 
Waterlogged

Waterlogged

20
3
I use ph up everyday does not stabilize, res is not covered but light is not hitting it, its under a table
 
tobh

tobh

Supporter
4,194
263
there's some obvious confusion in basic chemistry as well here. Sit down at your desk and pull out your notepad. This is important.

Never add a base to an acid. That's how you get volatile reactions. You always go basic then acidic. Not the other way.

The reason for this is say you have a solution of 4.0 at 800ppm. You decide to dump some potassium carbonate into the solution to raise the pH. Now, you see this shit floating in the solution and settling in the bottom of your res. This is called "crashing out." You've just create precipitates and completely destroyed the viability of those previously suspended minerals to be consumed by the plant. Not to mention, you've also introduced the potential for wild pH swings.

Now, let's go back to a link I posted earlier. I'll cliff note it here since there's obviously problems with following links and reading. I get it, it's hard to read these days. Can't make a tiktok or youtube video for yall, so this will have to suffice.

If you don't have potassium silicate, you should start with potassium carbonate. Add ~75ppm to your base water. This will be your buffer. You should have a pH of 9+. Let mix thoroughly. Now, add your pH up, likely phosphopric acid, and let mix thoroughly. Your target is 6.5. Proceed with adding your calmag and let mix five minutes or so, then proceed adding each individual nutrient part and allowing to mix five minutes each. Once everything's added and mixed, bring your pH to your target. You should have a stable pH.

The reason you add the base is because it prevents the acid from running rampant and nose diving like you're seeing. without the alkalinity the acid will do what acids do, and just keep driving the pH down.

Now, if your pH continues to dive after adding an alkaline buffer, then you've got bacteria issues and should be adding some kind of sterilizing agent since there's already a bacterial culture established and trying to use hydroguard or other beneficial bacteria simply won't take hold.
 
Waterlogged

Waterlogged

20
3
there's some obvious confusion in basic chemistry as well here. Sit down at your desk and pull out your notepad. This is important.

Never add a base to an acid. That's how you get volatile reactions. You always go basic then acidic. Not the other way.

The reason for this is say you have a solution of 4.0 at 800ppm. You decide to dump some potassium carbonate into the solution to raise the pH. Now, you see this shit floating in the solution and settling in the bottom of your res. This is called "crashing out." You've just create precipitates and completely destroyed the viability of those previously suspended minerals to be consumed by the plant. Not to mention, you've also introduced the potential for wild pH swings.

Now, let's go back to a link I posted earlier. I'll cliff note it here since there's obviously problems with following links and reading. I get it, it's hard to read these days. Can't make a tiktok or youtube video for yall, so this will have to suffice.

If you don't have potassium silicate, you should start with potassium carbonate. Add ~75ppm to your base water. This will be your buffer. You should have a pH of 9+. Let mix thoroughly. Now, add your pH up, likely phosphopric acid, and let mix thoroughly. Your target is 6.5. Proceed with adding your calmag and let mix five minutes or so, then proceed adding each individual nutrient part and allowing to mix five minutes each. Once everything's added and mixed, bring your pH to your target. You should have a stable pH.

The reason you add the base is because it prevents the acid from running rampant and nose diving like you're seeing. without the alkalinity the acid will do what acids do, and just keep driving the pH down.

Now, if your pH continues to dive after adding an alkaline buffer, then you've got bacteria issues and should be adding some kind of sterilizing agent since there's already a bacterial culture established and trying to use hydroguard or other beneficial bacteria simply won't take hold.
I put r/o in then i put tap water in till I hit about 70 to 80 ppm, my ph then is 6.8 then I put cal mag and the rest of my nutrients in and I'm at about 6.4 then I bring it down to 5.8, then for the 1st day or two it shoots back up to 6.8 then it drops every day into the 4's and I have to bring it back up with ph up, and I do see cloudiness and white filmy crap on the bottom and I don't have a lid on res maybe a little bit of light gets in but hardly any.
 
Waterlogged

Waterlogged

20
3
I put r/o in then i put tap water in till I hit about 70 to 80 ppm, my ph then is 6.8 then I put cal mag and the rest of my nutrients in and I'm at about 6.4 then I bring it down to 5.8, then for the 1st day or two it shoots back up to 6.8 then it drops every day into the 4's and I have to bring it back up with ph up, and I do see cloudiness and white filmy crap on the bottom and I don't have a lid on res maybe a little bit of light gets in but hardly any.
Never add a base to an acid. That's how you get volatile reactions. You always go basic then acidic. Not the other way.

Can you explain this in 2nd time grower language sorry I don't understand.
 
Top Bottom