threatco said:

My water always drifts a lot, 5.5 to 6.3-6.8 in 24hr Even if I put likr 400 ppm worth of up and down.

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MIMedGrower said:

Thats a great money saving tip!

Plus maybe in soil the weaker shorter lasting acid would not lower my medium ph over time.

That was why i stopped using ph down in the first place.

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JASONBROTHER said:

I have a way, because my pH was too high and i asked helps tons of time and puzzled me for a long time.

But at present, my own way is not bad. I can share it with u

after i mix the nutrient solution, use ph down of GH , almost a day later, my pH will return to about 7.0-7.5. At this time, I added some solid citric acid, which has the advantage of keeping pH of my water in a stable range (5.7-6.0),even in the next day, my pH remained stable in the range of 5.8-6.0,


but i never add citric acid after mixing the nutrient solution cause if i was in this way there will have many precipitates in my water.

If you don't use citric acid, and take pH down of GH every time , my cost will be very huge .

(at that moment i was in rock wool in flowering , my rock wool needs to be watered 3-4 times a day. I coundnt stay there without doing anything.

In fact, I now understand that the unstable temperature of water will definitely lead to the unstable pH of water. If the water temperature is kept at about 18 ° all the time (just like the water temperature required by hydroponics or aeroponics ). So the pH will absolutely super stable. It doesn't need any citric acid at all. A bottle of better pH down is enough

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threatco said:

The argument for citric/potassium carbonate buffering.

Keeping the pH of your hydroponic nutrient solution stable – Science in Hydroponics

scienceinhydroponics.com

My pH Balancing System for Hydroponic Growing – Science in Hydroponics

scienceinhydroponics.com

Long story short, the graph below shows the results for my simulations of “acid” or “base” additions using three different buffer agents. The blue line shows the change when citric acid/citrate is used as a buffering agent, the orange line shows when ammonia is used as a buffering agent and the yellow line shows when carbonate/citric acid is used as a buffering agent.

View attachment 984529

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Aqua Man said:

This is only citric/citrate etc. Now compare it to phosphoric or sulfuric. It's not bad in a system that uses auto ph dosing. The article is sooooo wrong on the harsh acid statement. It's take much less sulfuric or phosphoric acid because generally the citric acid is not as concentrated. In the end they all are the same. It's not the acid that burns it's the ph. So no matter what acid you use of you use the adequate amount to reach the same ph there is no difference in "harshness" they are the same. Now the concentrates are definitely different and some can cause severe burns. But that because their ph is much lower and that's what burns tissue... Beit plants, skin or other.

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threatco said:

What I was thinking made the difference is how the acid type and base type you choose reacts with each other.

For example, based on my testing anecdotal testing, I know my potassium hydroxide and phosphoric acid are completely failing to buffer the solution hardly at all. My noob chemist guess is because it is reacting quickly to form potassium phosphate and water. It can't buffer as effectively if it reacts and changes form, can it?

If this is true, then it would follow that various combinations are more effective then others. Some combinations are better at buffering at different ranges. Some are better over a wide range. And it is not based solely on their own respective acidic or basic strength.

Am I on the right track here?

Citric acid would react with Potassium Carbonate to make Potassium citrate. But not as quickly? Hence why more effective based on these tests?

I don't see the word harsh in the article. I see it using the term weak vs strong acids and bases.

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Aqua Man said:

I think your absolutely on to something there. Potassium bicarbonate is probably one of the most common ph up ingredients and that what I used to stabilize RO water.

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Glassdub said:

So the advantage over sodium bicarbonate is stability then? I actually have some potassium bicarbonate I forgot about that I used (failed attempt) for fungicide on garden veg, used SB a couple times as an up when I over downed.

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Aqua Man said:

This is only citric/citrate etc. Now compare it to phosphoric or sulfuric. It's not bad in a system that uses auto ph dosing. The article is sooooo wrong on the harsh acid statement. It's take much less sulfuric or phosphoric acid because generally the citric acid is not as concentrated. In the end they all are the same. It's not the acid that burns it's the ph. So no matter what acid you use of you use the adequate amount to reach the same ph there is no difference in "harshness" they are the same. Now the concentrates are definitely different and some can cause severe burns. But that because their ph is much lower and that's what burns tissue... Beit plants, skin or other.

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Aqua Man said:

You make a valid point most buffer will be potassium bicarbonate/silicate/hydroxide or calcium carbonate. I also feel a lot of it is due to poor aeration of source water prior to adding.

I honestly can't answer that because I don't have the knowledge but imo and experience citric is a 12 hr thing in a well aerated system.

Lol now I have to go buy some

JASONBROTHER said:

i really dont know why,
This question is very simple. We can find the answer more earsiler ----Google,
but we have a good chat. Ha ha, maybe this is the fun of growing marijuxxx

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