Alk too low and Baking Soda question

[NASAGeek]

This falls under the "I was stupid" clause that occasionally infects all of us....

I had just started this system and purchased 200 gallons of RODI. I'd added the salt and had gotten the specific gravity up.... all was going fine.

And then... I went to check the Calcium and Alk....

That's when I got stupid. I misread the Calcium test... and thought my calcium was WAY too low.... so I added a BUNCH of calcium.

And then, of course, I realized my mistake. Calcium WAY too high... and Alk shot way too low. Calcium is somewhere over 500... my test kit doesn't read high enough. Alk is 6.6... I add soda ash, but it goes right back to 6.6 after a while. pH is right around 8.1-8.2 at the moment. It'll spike up to 8.3 when I add the soda ash to the sump where my pH sensor is.... and it'll drift back down to 7.9 to 8.0. after a while.

I've been trying to raise the Alk.... adding Soda Ash. If my understanding of the chemistry is correct, the Soda Ash will consume the calcium and eventually the calcium will come down and the Alk will go up.

I really don't want to do a massive water change.

1) Is my understanding of the chemistry correct?
2) Can I use household sodium bicarbonate baking soda to inexpensively raise the Alk and lower the Calcium?
2) Other thoughts?

Trying to recover from my stupidity.

Thanks
Mark

[jml1149]

Is there life in this tank?

[NASAGeek]

Tank inhabitants seem to be doing great. Yellow Tang, Kole Eye Tank, 4 Pajama Cardinals, Clown fish.

I also found Arm&Hammer is fine to use.

[NASAGeek]

Also... this has been going on a few weeks since my "stupid incident". I've been gradually adding Alk.... I don't want to over shoot.

M

[NASAGeek]

I've been reading this....

http://www.advancedaquarist.com/2002/11/chemistry

Seems like I'm clearly in Zone 4 and doing the right thing... I guess I just need to be patient and keep going.

[bertoni]

Baking soda should be fine for dosing alkalinity. I agree that the problem will fix itself over time. You can use two syringes of titrant for the calcium test, and add the results, if you want an estimate of the level.

[NASAGeek]

A note in case someone else reads this later....

Arm&Hammer Baking Soda REDUCES the pH and INCREASES Alk.
Arm&Hammer Super Washing Soda INCREASES the pH and INCREASES Alk.

Important distinction. I'm using some of each, alternating to moderate my pH and get my Alk back up.

[homer1475]

You can also bake the baking soda to make soda ash(washing soda is tough to find here in the US). Which as you already know increases the PH which will increase the precipitate. The reason most of us do it in this manner is baking soda is food grade, while washing soda may have other things in it.

594grams of baking soda placed in a 350 degree oven for about an hour will give you soda ash.

[NASAGeek]

Originally Posted by homer1475

You can also bake the baking soda to make soda ash(washing soda is tough to find here in the US). Which as you already know increases the PH which will increase the precipitate. The reason most of us do it in this manner is baking soda is food grade, while washing soda may have other things in it.

594grams of baking soda placed in a 350 degree oven for about an hour will give you soda ash.

That's fascinating... I had no idea you could bake food grade baking soda to get soda ash. I'll give it a try.

I found Washing Soda at Walmart.... no perfumes or soap in it. I'll eventually get the Alk up.... seems to be getting close. THANKS

[homer1475]

Have a read through this(specifically the ALK parts as that's what your trying to do).

http://reefkeeping.com/issues/2006-02/rhf/index.php#5

If I was a betting man, I would dare say most reefers are using randy's DIY 2 part. While I do use his ALK part, some of the stuff to make magnesium and calcium are a bit hard to find for me, so I just use BRS bulk chemicals for those parts.

[rajilnaja]

Originally Posted by NASAGeek

That's fascinating... I had no idea you could bake food grade baking soda to get soda ash. I'll give it a try.

I found Washing Soda at Walmart.... no perfumes or soap in it. I'll eventually get the Alk up.... seems to be getting close. THANKS

Yeah being able to bake batches of it is a godsend.

[homer1475]

Forgot to add.....
After you make the DIY 2 part, you can use this calculator to determine the amount to use to raise your parameters a specific amount.

http://reef.diesyst.com/flashcalc/flashcalc.html

[homer1475]

If your trying to bring down your calcium by increasing your alk(increasing precipitate), be very careful with the precipitate as it can cause pump motors to seize, as well as coat everything that has some heat in it.

I had so much when I first started dosing that it burned out my heater.

[bertoni]

Baking soda will lower the pH temporarily by a tiny amount. It's less likely to cause precipitation, which can be a good thing. If you want to bake it, that's fine, too. That'll give a temporary pH boost, which can be useful for corals.

[NASAGeek]

Chemistry check..... I've been adding Baking soda/Washing Soda.... 5 tsp per day.... the pH spikes as you'd expect with the Washing Soda.... and dips a touch with the baking soda.

The Alk is not changing though.... I'm hovering around 6.7 to 7.

My chemistry theory is that the Alk is precipitating out the calcium and it just returns to it's steady state.... and that the water is still saturated with Calcium.... from my afore mentioned stupidity.

I feel like I should keep going.... Also.... I've tested the Alk with two different test kits to confirm the readings.

[bertoni]

The tank might be having some precipitation going on, although that might just be normal calcification from coralline, etc. I'd just watch the parameters and dose accordingly. 6.7-7 dKH is a reasonable range, although I'd try to raise it to 7-7.3. I don't know whether that might set off a precipitation event, though.

[NASAGeek]

I decided to "breakdown" and do a large water change. I don't like chasing this. RODI unit is pumping away making a bunch new water for me.

M