Hey Randy...

[melev]

I recently found out that my neighbors are getting divorced. The husband moved out three months ago, and the wife has been topping off with RO/DI and feeding the fish daily, if she remembers. The husband hasn't been back once in three months. I went over there yesterday to test the water and see where everything was parameter-wise, and pH was 7.88 and Alk was 6.0 dKH

This is on a 280g system with an 80g sump. How much baking soda will it take to bring the numbers up to something closer to NSW? Some of the corals look fluorescent yet translucent, such as the rose anemones and a frogspawn. I'm going back tomorrow to take a few pictures because I've never seen colors like this before!

I don't know how to figure the dosage since the system is so large. Also, should the baking soda be baked in the oven at 400F for an hour first to remove the CO2?

Ca was 440ppm
Sg was 1.0255
NO3 was 30ppm
PO4 was way out of whack, but I'm not trusting this kit.

[Randy Holmes-Farley]

How much baking soda will it take to bring the numbers up to something closer to NSW?

From this article:

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

"Baking Soda

To raise 50 gallons of tank water by 1 meq/L will require about 16 grams of baking soda (sodium bicarbonate; sodium hydrogencarbonate). Since a level teaspoon of baking soda weighs just under 6 grams, then 1 teaspoon will raise the alkalinity in that 50 gallons by ~0.4 meq/L (~1 dKH)."

I wouldn't bake this addition as the pH may rise too much. Once the alkalinity is where you want it, then routine additions can be baked.

[melev]

Okay, according to my math, 15 level tsp should bring it up to 7 dKH, and double that to reach 8 dKH right? I just got off the phone with her, and she wasn't too inclined to even do this much! :sad2: I'm going there tomorrow with a guy that wants to buy the tank, so I might just do it myself. :rolleyes:

[Randy Holmes-Farley]

OK, good luck.

FWIW, if you add the baking soda, dissolve it in some fresh water first. :)

I'd also recheck the math, although perhaps I missed something. 300 gallons, so 6 teaspoons will raise alkallinity by 1 dKH.

[melev]

Thanks for double checking my numbers. Thank god you did! I just re-read for the 4th time your message, and you said 1 tsp will raise it .4 meq/L and my math was using .4 dKH! I bet the tank wouldn't have rebounded too well.

That 300g number is a good guestimate since the LR & DSB displacement must be considered, and the 80g sump isn't full to the top.

I definitely recommended mixing the power in water first. I even suggested putting it in in three separate doses.

[Randy Holmes-Farley]

Sounds good. Good luck! :)