Calcium precipitation - How to reduce

[GoPitt88]

So I have a 55 gallon mixed reef, fully stocked with coral and a 3" Squamosa clam that seems to be healthy. I dose 88 ml of BRS calcium and soda ash daily, but also get some precipitate on areas of the glass and pumps (mp10 wetsides, filter pumps, protein skimmer pump). I keep my Alk around 8.0, CA around 400, and Mag around 1410. Any advice on minimizing ca precipitation, or is this normal? I normally need to clean the wetsides every 2 weeks, and pumps every month or so. And the areas of my glass, every few days. The glass seems to be areas of low flow, like the corners.

 

[GoPitt88]

Reading up on my BRS dosing pumps.....I just realized that I never calibrated them, meaning, I never tested to see how much they are ACTUALLY dosing per minute. I dose a total of 80 minutes per day (spaced out of course), but have assumed this entire time that each pump is dosing 1.1 ml per minute. I’ve read that they can actually be as high as 2.0 ml per minute. My pumps could be dosing at different rates. I need to calibrate them today!! [emoji4]

 

[GoPitt88]

Anybody have words of wisdom?

 

[GoPitt88]

Anybody? [emoji22]

 

[Flippers4pups]

Okay, dosing soda ash is likely the culprit. Try dosing sodium bicarbonate (baking soda) instead of sodium carbonate (baked baking soda) for alkalinity.

 

[Flippers4pups]

@GoPitt88, I had issues dosing soda ash long ago. Even if I dosed it in a high flow area and dosed it very slow.

I switched to straight baking soda (which is still used by the way) and the precipitation stopped.

The advantage of soda ash is higher pH for a short time and is highly concentrated. the con with using it is that a can precipitate very easily coating everything.

Using baking soda eliminates the precipitation problem.

 

[GoPitt88]

@GoPitt88, I had issues dosing soda ash long ago. Even if I dosed it in a high flow area and dosed it very slow.

I switched to straight baking soda (which is still used by the way) and the precipitation stopped.

The advantage of soda ash is higher pH for a short time and is highly concentrated. the con with using it is that a can precipitate very easily coating everything.

Using baking soda eliminates the precipitation problem.

Thanks, but if I use Sodium bicarbonate, my pH will drop below 8.0 Or shouldn’t I worry about that? Would love to try it. Also, I’ve been dosing equal parts of Alk and CA. If I switch to sodium bicarbonate, would I still dose equal amounts?

 

[GoPitt88]

Actually, I just looked at the BRS calculator, and looks like I would need to dose twice the amount of sodium bicarbonate as compared to soda ash to maintain the same alkalinity. Does that sound correct?

 

[Flippers4pups]

Thanks, but if I use Sodium bicarbonate, my pH will drop below 8.0 Or shouldn’t I worry about that? Would love to try it. Also, I’ve been dosing equal parts of Alk and CA. If I switch to sodium bicarbonate, would I still dose equal amounts?

It will lower pH, but only for a very short time. This is dependent also how much you dose at one time. Dose it during lights on for pH help. It really doesn't effect pH much because your only dosing small amounts at any one time. No worries on pH.

You would dose it along with calcium, but at a different amount as soda ash.

I use this calculator for dosing amounts:

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

Actually, I just looked at the BRS calculator, and looks like I would need to dose twice the amount of sodium bicarbonate as compared to soda ash to maintain the same alkalinity. Does that sound correct?

It will be more, yes. Refer to the calculator I provided.

Arm and Hammer baking soda is very cheap. Just baking soda with nothing added. Not baking powder!

 

[Flippers4pups]

I use Randy's recipe here:

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

Hope this helps.

 

[Randy Holmes-Farley Verified Community Expert]

The recipe for reduced precipitation is:

1. Lower pH. Switching to bicarbonate will help considerably.
2. Lower alk (7 dKH).
3. Lower calcium (390-420 ppm)
4. More diluted and/or slower addition of additives (both calcium and alk). Mag dosing rate is unimportant here.
5. Normal to high magnesium and phosphate
6. Allow organics to rise (less GAC, less skimming, less Purigen, etc.)
7. Stop dosing for a few days to allow fresh CaCO3 surfaces to get coated with organics/magnesium/phosphate to reduce further precipitation onto them.

 

[GoPitt88]

I use Randy's recipe here:

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

Hope this helps.

Thanks!!! One more question.....do you think if I dosed less, I’d get less precipitation, or do you think the precipitation would be the same and less would be available to my corals and clam?

 

[Flippers4pups]

Thanks!!! One more question.....do you think if I dosed less, I’d get less precipitation, or do you think the precipitation would be the same and less would be available to my corals and clam?

I'm not sure what it is your trying to do. Dosing less soda ash at any one time will help, but your overall need for alkalinity will take longer to be met.

Can be done. As Randy stated, you would still need to do what Randy suggests to keep the precipitation from happening. Seems a lot to do to just to use soda ash. Easier to use baking soda and call it a day. Jmtcw.

 

[GoPitt88]

The recipe for reduced precipitation is:

1. Lower pH. Switching to bicarbonate will help considerably.
2. Lower alk (7 dKH).
3. Lower calcium (390-420 ppm)
4. More diluted and/or slower addition of additives (both calcium and alk). Mag dosing rate is unimportant here.
5. Normal to high magnesium and phosphate
6. Allow organics to rise (less GAC, less skimming, less Purigen, etc.)
7. Stop dosing for a few days to allow fresh CaCO3 surfaces to get coated with organics/magnesium/phosphate to reduce further precipitation onto them.

Thank you SO MUCH! [emoji106][emoji16]

 

[GoPitt88]

Can be done. As Randy stated, you would still need to do what Randy suggests to keep the precipitation from happening. Seems a lot to do to just to use soda ash. Easier to use baking soda and call it a day. Jmtcw.

Going to try it.....thank you! [emoji16]

 

[GoPitt88]

I LOVE this forum!!!! [emoji3]

 

[Stigigemla]

Split the dosing into several dosings per day and Your problem will disappear. It is good to have at least 5 minutes between the different pumps to get the chemicals well mixed.
I would put this as an extension of #4 in Randys list.

 

[GoPitt88]

Split the dosing into several dosings per day and Your problem will disappear. It is good to have at least 5 minutes between the different pumps to get the chemicals well mixed.
I would put this as an extension of #4 in Randys list.

I already have both the Calcium and Alkalinity split into 8 dosing periods throughout the day.....spacing an hour between calcium and Alk.

 

[Stigigemla]

Normally You shouldnt get much precipipation with those levels.
I can see 2 possible issues:
1. Your values are wrong. Do another set of tests by a fellow reefer or buy new Ca, kH and Mg tests. I use Salifert. Triton Tests are reliable.
2. You dose into a low flow area. Try to move the dosing pump outlets to the sump inflow or skimmer outflow.

 

[Stigigemla]

I forgot one thing. The skimmer. If You use a small skimmer with low air intake Your pH can be driven very high. I recommend a skimmer with at least an air intake of a tank volume per hour or Your pH will go too high. If the pH goes over 8.4 (measured with a just calibrated pH meter) any time of the day You should replace some carbonate with bicarbonate.

In my tank with Carbonate I used to dose in the night to keep the pH up. In the day I didnt dose because the corals and algae keeps the pH up when light is on.