Precipitation with Alkalinity supplement?

[xtrstangx]

I have the DIY 2-part shown here:
http://www.advancedaquarist.com/issues/april2004/chem.htm

I'm using Recipe #1 and whenever I add alkalinity, whether its 1 drop, a capful, or whatever, I always get precipitation. The precipitation is bright white and they kind of look gellatinous. Irregular shaped, but they look soft.

Any idea what is going wrong? This is the first time I've made Recipe #1 and I am probably going to go back to recipe #2 after these bottles are over.

[mherndon]

First thing to do so we can assist you is to tell us what your calcium tests at as well as your Ph and alkalinity.

[xtrstangx]

<a href=showthread.php?s=&postid=7721694#post7721694 target=_blank>Originally posted</a> by mherndon
First thing to do so we can assist you is to tell us what your calcium tests at as well as your Ph and alkalinity.

Doh, I knew I forgot something.

pH: 8.26 now (was 8.09 when I added the supplement, but precipitation still occurs at 8.2+)
Calcium: 400 ppm (gotta add a splash more)
Alkalinity: 3.35 meq/L or 9.45 dKH
Magnesium: 1440 ppm

This is at 1.026 salinity.

[Boomer]

It is probably Magnesium Hydroxide, which will go right back into solution. I see your Mg++ is high. NSW is about 1290. And more will precip at higher pH, especially if there are zones where you are dosing where the pH is high.

[xtrstangx]

Interesting. It usually takes 30 minutes or so to go away, I figured the flow blew it around so it was dispersed.

Thanks Boomer! By the way, the 10:1 water/muriatic worked great!

[Randy Holmes-Farley]

Yes,it is normal.

here's normal:


What is that Precipitate in My Reef Aquarium?
http://reefkeeping.com/issues/2005-07/rhf/index.htm

from it:

http://www.reefkeeping.com/issues/2005-07/rhf/index.php#6

http://www.reefkeeping.com/issues/2005-07/rhf/images/Figure_3sm.jpg

[xtrstangx]

Mine isn't so much of a cloud like that. It resembles cottage cheese minus the liquid. Is it still the Magnesium?

[Boomer]

I know what you mean it is the same thing. Whether it is a cloud or pasty like mass it is the same. Its appearance is a function of the water parameters. Same thing for the amount of time it remains in view, i.e, 1 min, 10 min, 1 hr etc...The longer it takes to dissipate and the more cloud =>pasty/ cheese=> chunky=> = more of a ionic imbalance and the more one needs a water change or the longer to dissipate = 10 sec=> 30 sec => 1min=> 30min=>etc. =more in need of a water change also

[Randy Holmes-Farley]

Mine isn't so much of a cloud like that. It resembles cottage cheese minus the liquid. Is it still the Magnesium?

That is what it would look like if it settled. Add it to a high flow area so that doesn't happen.