Reducing alkalinity ?

aeras1131 · Nov 25, 2017

I meant to say something like this. If you are attempting keep low params, I would use a low param salt and simply maintain with a doser

If you don't put something in that matches, It makes it more difficult to do larger water changes if necessary. Sorry All

Randy Holmes-Farley · Nov 25, 2017

No problem [emoji3]

Zack K · Nov 25, 2017

aeras1131 said:
I meant to say something like this. If you are attempting keep low params, I would use a low param salt and simply maintain with a doser If you don't put something in that matches, It makes it more difficult to do larger water changes if necessary. Sorry All

l see where your coming from but unfortunately the OP is in Vietnam. Where IO is all she has. Good point though![emoji2]

AB_Reefer · Nov 27, 2017

aeras1131 said:
I meant to say something like this. If you are attempting keep low params, I would use a low param salt and simply maintain with a doser If you don't put something in that matches, It makes it more difficult to do larger water changes if necessary. Sorry All

Totally agree with you.. but I don' have a low parameters salt available at any lfs .. won't mind the extra 30 bucks for an easier more stable option..
Allthough I am already paying 30 extra for IO .. as it's 80 USD per bucket here

AB_Reefer · Nov 27, 2017

FTS..
Battling cyno at the moment.. hope can get it under control soon.

piranhaman00 · Apr 25, 2020

I just used this Muriatic acid technique to lower alkalinity, worked great, now the pH is below 7.5, how long does airing it out take to bring the pH back up?

Randy Holmes-Farley · Apr 25, 2020

piranhaman00 said:
I just used this Muriatic acid technique to lower alkalinity, worked great, now the pH is below 7.5, how long does airing it out take to bring the pH back up?

Depends on the aeration. The more you aerate, the faster it goes. Shouldn't take more than a day, but if you are in a closed room, the room CO2 may be higher now.

piranhaman00 · Apr 25, 2020

I’m aerating next to open window with fan blowing in, I was hoping it would just take a few hours, thanks

Randy Holmes-Farley · Apr 25, 2020

piranhaman00 said:
I’m aerating next to open window with fan blowing in, I was hoping it would just take a few hours, thanks

With enough turnover it might!

runjmb · Nov 6, 2020

Randy Holmes-Farley said:
It won't impact anything else except pH, which it lowers a lot. Aeration will slowly bring it back up.

Here's a copy and past of an old post of mine for a guy who wanted to use it to drop the alk from 13 to 7 dKH in 13 gallons of salt water.:

Yes, you just add the acid. Be very careful with straight muriatic acid. It can easily burn you, especially your eyes.

The "acidity" (that being essentially negative alkalinity) of normal (not low fume type) muriatic acid straight from the bottle is about 11,000 meq/L.

So adding 1/11,000 of the water volume as this acid will drop alkalinity by 1 meq/l (2.8 dKH).

You want a drop of 13-7 = 6 dKH, or 2.1 times that amount, so you'd add 1/5,100th of the water volume.

13 gallons ~ 49 L

1/5100 of 49 L = 9.6 mL

So I'd add 5 ml and stir well for a few minutes and see what alkalinity you get. Then dose again assuming it seems on the right track.

You'll need to aerate well after adding the acid to blow off the excess CO2 and bring up the pH.

hi mate can you please go through the calculation on how to calculate that 11000 meq/L?
I am using hydrochloric acid from a hardware store with a concentration of 320grams/litre. I couldn’t find muriatic acid but I assume it is the same thing

Randy Holmes-Farley · Nov 6, 2020

runjmb said:
hi mate can you please go through the calculation on how to calculate that 11000 meq/L?
I am using hydrochloric acid from a hardware store with a concentration of 320grams/litre. I couldn’t find muriatic acid but I assume it is the same thing

Sure. Yours is a bit weaker than the calculation.

HCl weighs 36.5 grams per mole.

320 grams per liter of HCl means 320/36.5 = 8.8 molar, which is 8,800 meq/L of acidity. That means it would subtract 8,800 meq/L of alkalinity if you used a full liter.

8,800 meq/L is the same as 2.8 dKH/meq/L x 8,800 meq/l = 24,640 dKH.

Thus, you can think of it as -24,640 dKH.

runjmb · Dec 4, 2020

Randy Holmes-Farley said:
It won't impact anything else except pH, which it lowers a lot. Aeration will slowly bring it back up.

Here's a copy and past of an old post of mine for a guy who wanted to use it to drop the alk from 13 to 7 dKH in 13 gallons of salt water.:

Yes, you just add the acid. Be very careful with straight muriatic acid. It can easily burn you, especially your eyes.

The "acidity" (that being essentially negative alkalinity) of normal (not low fume type) muriatic acid straight from the bottle is about 11,000 meq/L.

So adding 1/11,000 of the water volume as this acid will drop alkalinity by 1 meq/l (2.8 dKH).

You want a drop of 13-7 = 6 dKH, or 2.1 times that amount, so you'd add 1/5,100th of the water volume.

13 gallons ~ 49 L

1/5100 of 49 L = 9.6 mL

So I'd add 5 ml and stir well for a few minutes and see what alkalinity you get. Then dose again assuming it seems on the right track.

You'll need to aerate well after adding the acid to blow off the excess CO2 and bring up the pH.

Hi Randy,

would you please go over the numbers in detail and explain how you come up with them. I’m interested to learn more so I can relate this to different concentrations of muriatic acid. I wanted to know how you got to the number that adding 1/11000 reduces your alkalinity by 2.8.