How can I lower the alkalinity in fresh saltwater mix?

[Rawsreef]

I got some purple bucket IO mixed to 1.026 and I just tested, the alk was 11.3. Ive been having issues with some acans not looking too well. I think an alk spike is the case. I used to buy sea water at the LFS, but since I switched to mixing salt for my WC's. Some things didn't react too well.

I normally kept my alk around 8~ ish, since I switched my alk has spiked to 10+. It's been months now of using this salt in hopes my tank would acclimate to the higher alk. But it's just not doing it.

I still have some buckets of salt, and some freshly mixed salt water I would like to use, and not waste.

Is there a way I can easily bring the alk to the desired 8-9 target range?

I read about adding muratic acid or something like that?? Don't feel too comfortable with that. Also read about sodium bisulfate which sounds safer but I'm still no chemist lol....


Are these the only ways to bring the alk down?

 

[blaxsun]

Mix a different brand of salt and combine the two?

 

[Randy Holmes-Farley]

I got some purple bucket IO mixed to 1.026 and I just tested, the alk was 11.3. Ive been having issues with some acans not looking too well. I think an alk spike is the case. I used to buy sea water at the LFS, but since I switched to mixing salt for my WC's. Some things didn't react too well.

I normally kept my alk around 8~ ish, since I switched my alk has spiked to 10+. It's been months now of using this salt in hopes my tank would acclimate to the higher alk. But it's just not doing it.

I still have some buckets of salt, and some freshly mixed salt water I would like to use, and not waste.

Is there a way I can easily bring the alk to the desired 8-9 target range?

I read about adding muratic acid or something like that?? Don't feel too comfortable with that. Also read about sodium bisulfate which sounds safer but I'm still no chemist lol....


Are these the only ways to bring the alk down?

Those are the two best ways. There are recipe threads on them if you are interested. It is very easy.

 

[Rawsreef]

Those are the two best ways. There are recipe threads on them if you are interested. It is very easy.

I'll probably be more comfortable with using the sodium bisulfate. I'll look into buying some

 

[Reef.]

I used seachem acid buffer, only a small tank so I didn’t try and source a cheap alternative.

If going that route make sure to mix for 24 hours to get the ph back to normal, or use an air stone then it only takes a couple of hours.

 

[Rawsreef]

I used seachem acid buffer, only a small tank so I didn’t try and source a cheap alternative.

If going that route make sure to mix for 24 hours to get the ph back to normal, or use an air stone then it only takes a couple of hours.

I actually have some of that stuff on hand (just a little I think) but I think that stuff is for raising the alkalinity not lowering ?

 

[Reef.]

I actually have some of that stuff on hand (just a little I think) but I think that stuff is for raising the alkalinity not lowering ?

Lowering, I used it for the same salt to get to 7dkh, make sure it’s acid buffer.

 

[Rawsreef]

Is this what I need? Is there a cheaper brand I can use or is this a good price?

 

[Rawsreef]

Lowering, I used it for the same salt to get to 7dkh, make sure it’s acid buffer.

The acid buffer says it's for pH?

Edit- now I see that it says turns KH into CO2

This is the one I have

 

[Rawsreef]

On second thought, I might be going the acid route. I just read it's the same stuff used for pools, which I may have some around the house as we have a pool. Not sure if I can use the same stuff but it will probably be easier to get, and I'll probably be doing my water changes tomorrow vs in a few days.

 

[Reef.]

Be careful what you use as not all are as pure as others, you don’t know what the product may also contain, this is the reason I went with Seachem.

 

[Randy Holmes-Farley]

The Seachem acid buffer is the right material, but without a purity guarantee and somewhat more expensive than food grades.

The modernist pantry item is the wrong material. Be sure it says sodium bisulfate, not metabisulfite.

This is the thread on it:

Sodium Bisulfate to Reduce Alkalinity in New Salt Water or in Display Tanks

I just want to record these calculations in their own thread to refer back to in other threads. When alkalinity is too high in new salt water or in a display tank, acid can be used to lower the alkalinity. You can easily use muriatic acid (hydrochloric acid), or sodium bifulfate (e.g...

www.reef2reef.com

 

[Rawsreef]

The Seachem acid buffer is the right material, but without a purity guarantee and somewhat more expensive than food grades.

The modernist pantry item is the wrong material. Be sure it says sodium bisulfate, not metabisulfite.

This is the thread on it:

Sodium Bisulfate to Reduce Alkalinity in New Salt Water or in Display Tanks

I just want to record these calculations in their own thread to refer back to in other threads. When alkalinity is too high in new salt water or in a display tank, acid can be used to lower the alkalinity. You can easily use muriatic acid (hydrochloric acid), or sodium bifulfate (e.g...

www.reef2reef.com

If I were to use muratic acid, can I get it at a local hardware store? Like this stuff :

 

[Randy Holmes-Farley]

Yes, just note that the purity may be variable and it is harder to safely use due to fumes and possible spillage. Be certain to wear safety classes and not spill it on yourself.

 

[Nano_Man]

I used this when high Alk
But I have changed to natural sea water Alk bang on as the other parameters are also bang on

 

[Randy Holmes-Farley]

I used this when high Alk
But I have changed to natural sea water Alk bang on as the other parameters are also bang on

Yes, that's the right chemical, but it lacks purity info and is more expensive than food grade chemicals.

 

[Rawsreef]

Yes, just note that the purity may be variable and it is harder to safely use due to fumes and possible spillage. Be certain to wear safety classes and not spill it on yourself.

I have some experience handling this stuff, I've poured it into pools before.

This is what I was able to find. What would be the mixing ratio for this stuff?

Also is there any chance I'm going to be introducing some other unwanted chemicals that can be in this stuff? Or is this 100% safe? Lol

 

[Randy Holmes-Farley]

I have some experience handling this stuff, I've poured it into pools before.

This is what I was able to find. What would be the mixing ratio for this stuff?

Also is there any chance I'm going to be introducing some other unwanted chemicals that can be in this stuff? Or is this 100% safe? Lol

As I stated, purity may vary. No easy way to know, but I've not heard of any purity-related problems using muriatic acid.

Here's a cut and paste for standard (~35%) muriatic acid. Your looks a little less potent.

You can use muriatic acid or certain freshwater buffers to lower alk.
Both will lower pH similarly and a lot. There's no way around the pH lowering when reducing alkalinity. You do not want to add CO2. You want to remove CO2 from the tank via aeration.

For that reason, it is best to do it in water change water that is aerated to raise pH before using, or to do it very slowly in the tank (over many days).

The "acidity" (that being essentially negative alkalinity) of 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).

I would not drop more than 1 dKH per day due to the big pH drop in a reef tank, but in new salt water it is fine.

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

 

[Rawsreef]

As I stated, purity may vary. No easy way to know, but I've not heard of any purity-related problems using muriatic acid.

Here's a cut and paste for standard (~35%) muriatic acid. Your looks a little less potent.

You can use muriatic acid or certain freshwater buffers to lower alk.
Both will lower pH similarly and a lot. There's no way around the pH lowering when reducing alkalinity. You do not want to add CO2. You want to remove CO2 from the tank via aeration.

For that reason, it is best to do it in water change water that is aerated to raise pH before using, or to do it very slowly in the tank (over many days).

The "acidity" (that being essentially negative alkalinity) of 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).

I would not drop more than 1 dKH per day due to the big pH drop in a reef tank, but in new salt water it is fine.

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

1/11,000 of water volume to drop 2.8 dkh.

let me make sure I understand correctly,

if I wanted to lower the alk of 11k gallons by2.8 dkh I would do 1 gallon of muratic acid?


in my case the alk is 11.3 on about 50ish gallons of water which I want to bring to about 8.5

to find how much I would need I take

(1/11,000) x 50 = approx .0045454 gallons which converts to approx 17 mls?


Does that sound right?

 

[Reef.]

Probably doesn’t help must but I used only 5 grams of acid buffer to lower 6.5galloms by 5dk.

May help with a cost analysis and amounts.

You could always try making up a gallon or even just a litre to work out dosage.