Alkalinity boost help

[Brockly]

Help with alkalinity.

Any thoughts on this...
I have a 20 gallon coral Qt. It has just a sponge filter and rack in it. Has about 15 small coral frags. 1/2 zoanthids 1/2 sps. Lit with mars aqua

My salinity was 1.026, magnesium was 1330, calcium 400, dkh was 7.5

I wanted to boost dkh up so dosed 20 ml 1ml/g)of just the alk part of 2 part which said it would raise dkh by 2. I also dosed 2 quart of kalkwasser as top off thst day. 24 hours later instead of having the expected 9.5 dkh its was 7.6?

Why did it not raise?

 

[outssider]

my bet is that it precipitated out mainly because the kalk raised the ph. check the calcium, that should be lower too! did you use sodium carbonate or bicarbonate ? sodium carbonate will raise the ph even more and increase the chance of precipitation. try dissolving bicarbonate (baking soda) in ro/di water and dripping it slowly into the frag tank no kalk.

 

[Brockly]

My 2 part is made of soda ash so carbonate. I use thst as my ph is always 8.2 ish(I can't tell the difference between 8.25 and 8.3 on salifert doh test) I checked the calcium and it wasn't really lower then I expected. It was 390 but I have a hard time maintaining it at 420 as I use instant ocean and it is so low on everything. (I need to switch) do I drip the baking soda the same as kalk. 1 teaspoon per half gallon of rodi water?

I have had the tank up for 2 months and have yet to get a stable alk calcium and mag, it's been pretty frustrsting

 

[karimwassef]

I keep my Mg over 1500 to minimize precipitation at high pH 8.3 and high Ca >550 without compromising dKH - keeping it above 9 now...

Also, time is important. Drip in very very slowly.

 

[tmz]

Precipitation is the likely cause; primarily from too much alk.

I use instant ocean and it is so low on everything. (I need to switch)


It's not actually; see this sticky:

http://www.reefcentral.com/forums/showthread.php?t=2554264

Try post #18 as a start.

 

[PAXpress]

Help with alkalinity.

Any thoughts on this...
I have a 20 gallon coral Qt. It has just a sponge filter and rack in it. Has about 15 small coral frags. 1/2 zoanthids 1/2 sps. Lit with mars aqua

My salinity was 1.026, magnesium was 1330, calcium 400, dkh was 7.5

I wanted to boost dkh up so dosed 20 ml 1ml/g)of just the alk part of 2 part which said it would raise dkh by 2. I also dosed 2 quart of kalkwasser as top off thst day. 24 hours later instead of having the expected 9.5 dkh its was 7.6?

Why did it not raise?

You may want to try baking soda mixture instead, I had constant problems with alk staying above 7.5 and constantly falling back to 5.9 or lower and the baking soda helped a lot (along with a complete clean out of my sump). Check out this link http://www.reefkeeping.com/issues/2006-02/rhf/ Specifically this tidbit:
" Recipe #2, Part 2: The Alkalinity Part

Dissolve 297 grams of baking soda (about 1 1/8 cups) in enough water to make 1 gallon total. This dissolution may require a fair amount of mixing. Warming it speeds dissolution. This solution will contain about 950 meq/L of alkalinity (2660 dKH). As mentioned earlier, Arm & Hammer is a fine brand of baking soda to use in these recipes. Be sure to NOT use baking powder. Baking powder is a different material that often has phosphate as a main ingredient.

Once these two solutions are created, they can be added as frequently as necessary to maintain calcium and alkalinity. For further dosing instructions, see below. "


You don't have to mix this much total, but a small amount would raise the alk steadily. Also you don't want to bake it because it will turn the baking soda into sodium carbonate instead and will raise the ph. You want the actual baking soda I believe and precipitation will not be as much of an issue.