Alkalinity consumption rate

[asylumdown]

I used to use baking soda, but even when mixing with DI water, I'd get this weird chalky precipitate at the bottom of the container. The tropic Marin stuff doesn't do that. It is expensive, however, and if Tim considers 128 grams/day low, I might have to switch.

Tropic Marin recommends dissolving 420 grams of the alk and 380 grams of the calcium in 5 L of water. At 540 mL a day and rising, I'm burning through my 3 gallon dosing containers pretty fast. How much do you think I could increase the concentration of each without risking supersaturation precipitation?

[mark]

assuming you're mixing a solution, from RHF 2 part guide

[TimT]

Originally Posted by asylumdown

I'd get this weird chalky precipitate at the bottom of the container.

That might be because either your trying to mix too much bicarb into the amount of water or the water is cooling too much after dissolving and the bicarb won't stay in solution. I find it works better if you warm the water to about 80°f. I mix at a concentration of 86 grams sodium bicarb to 1 litre of water. I stir it for 15 minutes to make sure it's all dissolved.

[PFoster]

Hmm.. very cool tip Tim, I will try this.
I have found the precipitation from sodium bicarb too and i just don't use the bottom tiny bit of the container.
But i will definitely try this!

[Myka]

I think it's kind of funny (cute?) when people start dosing, and they say "I dose more and more and I can't keep up." Just keep dosing more. As your parameters stabilize the growth will increase too, so then you'll be behind again. By now you should have a good idea how much you increase the dosing and how much that affects your numbers. Just keeping increasing until you find the happy spot, but continue weekly testing until your tank is full (of corals) and the increase in consumption is less. A growing tank will always have a greater and greater demand until you're fragging just as much as is growing. I can't remember if you mentioned magnesium at all? You're testing that as well, right? You're in the 1300-1400 ppm range?

Originally Posted by TimT

That might be because either your trying to mix too much bicarb into the amount of water or the water is cooling too much after dissolving and the bicarb won't stay in solution. I find it works better if you warm the water to about 80°f. I mix at a concentration of 86 grams sodium bicarb to 1 litre of water. I stir it for 15 minutes to make sure it's all dissolved.

I do this too, except I use a MJ400 to do the mixing. Using warm water makes a big difference when mixing sodium (bi)carbonate.

[Snappy]

Regarding any precipitate at the bottom of the container - I do get some but I really don't worry about it. I draw the solution through an air stone so I don't clog up my hoses or pumps. I also run a small powerhead in the alk tank to help things stay in solution.

[Myka]

That's interesting about the precipitate from the alkalinity solution. I don't get any precipitate from either Fauna Marin or Tropic Marin. TM mixes a lot easier than FM for some reason, but they both dissolve completely.