Dosing alk and mag?

[Notsolostfish]

My mag is at 1260, and my alk is at 7.2 i want to increase both to alk 8.5 and mag 1400. Im using red sea liquid. My ph right now 8.21 during night and 8.28 during day 8.3 would raising alk increase PH? and how much mag do i need to increase a day? it says i need 741.9 ml; from red sea mag to get to 1400. So i need some insight here? How much ML do i need a day and how much time apart thank you.

 

[blaxsun]

I'd double-check those calculations - that seems like a f**k ton of magnesium. Unless you have an insanely big tank...

 

[Notsolostfish]

I'd double-check those calculations - that seems like a f**k ton of magnesium. Unless you have an insanely big tank...

 

[blaxsun]

Add 10ml a day to start and test every 48 hours. Just for comparison, I dose <2ml of magnesium daily to maintain 1450ppm on a 200-gallon system.

Also, look into powdered forms for the magnesium (etc.), ie: Red Sea, Nyos, etc. Way cheaper than the liquid.

 

[Notsolostfish]

Add 10ml a day to start and test every 48 hours. Just for comparison, I dose <2ml of magnesium daily to maintain 1450ppm on a 200-gallon system.

Also, look into powdered forms for the magnesium (etc.), ie: Red Sea, Nyos, etc. Way cheaper than the liquid.

I have to use the bottles i have, and after that ill switch to pwoder ill probably do 53ml a day for mag. Would raising alk raise my PH?

 

[SliceGolfer]

How much liquid you need to dose depends on the product. I agree that mixing your own is more cost effective. It's recommended not to increase mag more than 100ppm per day. To your other question, yes, raising alk does have an effect on pH. Adding too much alk supplement can cause your pH to rise rapidly, which might be undesirable. Second, raising the alk level will raise the baseline of pH.

 

[blaxsun]

I have to use the bottles i have, and after that ill switch to pwoder ill probably do 53ml a day for mag. Would raising alk raise my PH?

Just be sure to test often. That's still a large dose of magnesium...

 

[Notsolostfish]

How much liquid you need to dose depends on the product. I agree that mixing your own is more cost effective. It's recommended not to increase mag more than 100ppm per day. To your other question, yes, raising alk does have an effect on pH. Adding too much alk supplement can cause your pH to rise rapidly, which might be undesirable. Second, raising the alk level will raise the baseline of pH.

Okay so what do i do here i don't want to sit at 7.3 kh i want my kh back to 8.1-8.5 but at the same time i don't want to go over my ph which is 8.28

 

[Pistondog]

You can dose sodium hydroxide or baking soda for extra alk. The sodium hydroxide will also raise ph.
Be careful what you store the NaOH in, it is caustic and can eat thru some plastics. I use a glass jar.

 

[Notsolostfish]

You can dose sodium hydroxide or baking soda for extra alk. The sodium hydroxide will also raise ph.
Be careful what you store the NaOH in, it is caustic and can eat thru some plastics. I use a glass jar.

Didn't @Randy Holmes-Farley said rising for the PH is temporary? when dosing alk?

 

[SliceGolfer]

Okay so what do i do here i don't want to sit at 7.3 kh i want my kh back to 8.1-8.5 but at the same time i don't want to go over my ph which is 8.28

+1 to @Pistondog's response, use a bicarbonate additive like baking soda to raise alk but not pH.

 

[Randy Holmes-Farley Verified Community Expert]

Didn't @Randy Holmes-Farley said rising for the PH is temporary? when dosing alk?

Yes, but in reality, everything one does to raise pH is temporary unless you keep doing it.

 

[Notsolostfish]

Yes, but in reality, everything one does to raise pH is temporary unless you keep doing it.

My plan was to rise my alk to 8.1-8.2 where my salt level was. Would that give me a hard time with PH? Because i alrwady use a co2 scrubber and my ph during day is 8.28

 

[Randy Holmes-Farley Verified Community Expert]

My plan was to rise my alk to 8.1-8.2 where my salt level was. Would that give me a hard time with PH? Because i alrwady use a co2 scrubber and my ph during day is 8.28

Alk is only half the equation on pH, and rarely is it the cause of low pH.

Low pH is caused by excess CO2. An alk of 7-11 dKH is fine, IMO.

 

[Notsolostfish]

Alk is only half the equation on pH, and rarely is it the cause of low pH.

Low pH is caused by excess CO2. An alk of 7-11 dKH is fine, IMO.

No I understand that. But my question was i dint want my PH to go wayyy up when i dose alk above 8.3

 

[Randy Holmes-Farley Verified Community Expert]

No I understand that. But my question was i dint want my PH to go wayyy up when i dose alk above 8.3

It won't. In terms of the actual pH differences caused just by an alk difference from 7.3 to 8.5 dKH is only about 0.07 pH units.

 

[Notsolostfish]

It won't. In terms of the actual pH differences caused just by an alk difference from 7.3 to 8.5 dKH is only about 0.07 pH units.

I literally added half a dose of red sea alk. And my ph fron 8.24 to 8.4 immediately how bad did i mess up?

 

[Notsolostfish]

It won't. In terms of the actual pH differences caused just by an alk difference from 7.3 to 8.5 dKH is only about 0.07 pH units.

Never mind i dosed in the same chamber of the apex ph probe now went back to 8.28 lol

 

[Randy Holmes-Farley Verified Community Expert]

Never mind i dosed in the same chamber of the apex ph probe now went back to 8.28 lol

Yes, the local rise is going to be much more than in the display.

 

[Spare time]

You can dose large amounts of magnesium at a time imo.