Raising KH with baking soda

[Jekyl]

I'm ashamed to admit I've been neglectful. Being a new small business owner who was subject to the rona the last year has been rough. Business is still slow but I've decided to vent my stress into my tank. Working now to get everything back on track. My KH tested with salifert is right around 5. I'd like to use the arm and hammer method to get it back where it should be. I have a 90 gallon tank, no sump. My question is 2 part:
1 How much soda should I add to the system
2. How quickly should I try and raise it?

 

[Reverend Turtle]

Raise it slowly. Like .1 a day. Sudden swings in either direction can cause death to your live stock.
I don't know exactly how much baking soda to add, but I used to add 1 table spoon to five gallons of top off water 20 or so years ago. Now days there are much better ways and products to use. Like one of the 2 part systems.

 

[Jekyl]

Trying to use materials on hand before spending money that I shouldn't first.

 

[homer1475]

Google Randy's DIY 2 part.

Depending on your PH, you can either bake the baking soda(soda ash) for an small increase in PH. Or just use plain baking soda(Sodium bicarbonate).

Either way should be mixed in RO/DI, and do not add more then 1DKH worth in 24 hours. This calculator will help you with how much to add.

Reef Chemistry Calculator

 

[Jekyl]

Thanks for that. I added 3 teaspoons to around 2 gallons of top off water that I'll add over the next 3 days and I'll retest. Thanks for the response!

 

[homer1475]

Thats not going to do a whole lot.

Randys recipe is 1 1/8C(297 grams) in enough RO/DI to make1 gal total.

 

[Jekyl]

This says 3.8tsp

 

[homer1475]

Directly added, not mixed in RO/DI. Well not exactly not mixed, but only enough RO/DI to make it watery.

Heres randy's recipe:

http://reefkeeping.com/issues/2006-02/rhf/index.php#11

Alkalinity recipe 2 is just plain baking soda dissolved in RO/DI, and you would use randys recipe 2 in that calc I linked to.

 

[Jekyl]

@Randy Holmes-Farley
That seems like a ton to be adding. Want to be sure before I kill everything

 

[KrisReef]

Do you have corals, or just fish?

 

[Marty's Reef]

Try this Reef Chemistry Calculator (diesyst.com)

 

[homer1475]

I don't think your understanding.......

You don't add it all at once. You make the premade solution, then using the calc, figure out how much to add. Don't forget with the recipe your adding quite a bit of water, so it may seem like a lot, but in reality it isn't.

For my tank(85G total water volume):

I would make the solution, then to go from 5 to 7( I would only go from 5 to 6 in 24 hours), I would have to add 242.8ML of the premade solution.

 

[Randy Holmes-Farley Verified Community Expert]

This calculator shows how much is needed:

@Randy Holmes-Farley
That seems like a ton to be adding. Want to be sure before I kill everything

lol

That is a reliable calculator.

I'd boost alk by 0.5 dKH per day.

 

[Jekyl]

This calculator shows how much is needed:


lol

That is a reliable calculator.

I'd boost alk by 0.5 dKH per day.

I'm not questioning your calculations one bit. I'm not smart enough to do so. I'm just trying to figure it all out. I'm not the best at reef chemistry and want to make sure I'm not doing harm instead of good. My thoughts through the calculator is that from my screenshot I would need to add a total of 3.8tsp of baking soda to the system to get from 5kh to 7.

 

[Jekyl]

Also while introducing it slowly so 3.8tsp with my top off water of a few gallons over the next few days

 

[homer1475]

You do, but adding to 2 gallons of water is going to dilute it so much it will have probably close to 0 impact on your KH.

Read the warning on the bottom of your screenshot, you only mix it in enough water to make it soluble.

The easier way is to mix up randys recipe 2, then use the calc for that.

 

[Randy Holmes-Farley Verified Community Expert]

Also while introducing it slowly so 3.8tsp with my top off water of a few gallons over the next few days

That's a fine plan.

 

[Randy Holmes-Farley Verified Community Expert]

I'm not questioning your calculations one bit. I'm not smart enough to do so. I'm just trying to figure it all out. I'm not the best at reef chemistry and want to make sure I'm not doing harm instead of good. My thoughts through the calculator is that from my screenshot I would need to add a total of 3.8tsp of baking soda to the system to get from 5kh to 7.

It's not my calculation. lol

The bigger concern is faulty testing leading you to dose when its not necessary, more than anything else.

Have you tried the kit on some new salt water to see if you are using it right?

 

[homer1475]

You really think so randy? Wouldn't it dilute it so much it would have close to 0 impact? Maybe I;m misunderstanding the science here?

 

[Randy Holmes-Farley Verified Community Expert]

You really think so randy? Wouldn't it dilute it so much it would have close to 0 impact? Maybe I;m misunderstanding the science here?

If you add the same amount of total solid material (say, 3 teaspoons), it doesn't matter the amount its dissolved in (assuming it is not so huge that it is like the tank volume and hence expands the tank volume significantly. 100 mL? 1 L? 10 L?