Hellow fellow Hydro growers,
About 3 weeks ago I had to switch from Essentials pH down to GH pH down solution as the Essentials bottle had finished.
Ever since, I've seen large swings in pH occur before finally stabilising to my intended level - 5.9 - 6.1.
Water: 25L / base pH 7.5 / ppm 280-300.
The Essentials pH down would need about 10 - 12 ml to get my nute mixed water from 7.5 to 5.9, and it would stay there until water change every 7 days.
The GH pH down is another story.
Initially needs 36ml to get it down to 5.9.
24 hrs later its at 7.0
add another 15 ml and about 11 hrs later it stabilises at 6.0
2nd water change with GH pH down:
36ml pH down, pH is at 4.8.
18 hrs later its at 5.3
another 10 hrs and its at 6.7.
add another 7ml pH down to bring it to 6.0
Needless to say, I think this is a big cause of stress to the plants.
Has anyone else seen these big pH swings using GH pH down?
GH says that its pH down is based on "Food grade" phosphoric acid.
Found an article on Wikipedia about Phosphoric acid, and a graph shoing 3 distinct 'buffer zones' where 3 different forms of Phosphoric acid are present, depending on the pH level.
If the concentrated version of it is around the 1st buffer zone, how long would it take to transistion into the second form?
Maybe someone with a chemistry background could weigh in?
Thanks all, and would love to read your observations.
About 3 weeks ago I had to switch from Essentials pH down to GH pH down solution as the Essentials bottle had finished.
Ever since, I've seen large swings in pH occur before finally stabilising to my intended level - 5.9 - 6.1.
Water: 25L / base pH 7.5 / ppm 280-300.
The Essentials pH down would need about 10 - 12 ml to get my nute mixed water from 7.5 to 5.9, and it would stay there until water change every 7 days.
The GH pH down is another story.
Initially needs 36ml to get it down to 5.9.
24 hrs later its at 7.0
add another 15 ml and about 11 hrs later it stabilises at 6.0
2nd water change with GH pH down:
36ml pH down, pH is at 4.8.
18 hrs later its at 5.3
another 10 hrs and its at 6.7.
add another 7ml pH down to bring it to 6.0
Needless to say, I think this is a big cause of stress to the plants.
Has anyone else seen these big pH swings using GH pH down?
GH says that its pH down is based on "Food grade" phosphoric acid.
Found an article on Wikipedia about Phosphoric acid, and a graph shoing 3 distinct 'buffer zones' where 3 different forms of Phosphoric acid are present, depending on the pH level.
If the concentrated version of it is around the 1st buffer zone, how long would it take to transistion into the second form?
Maybe someone with a chemistry background could weigh in?
Thanks all, and would love to read your observations.
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