CO2 Scrubber Causing Abiotic Precipitation

[Trenton Henderson]

Hey all,

Just wanted to share my experiences and see if anyone else has had this issue. I added a CO2 scrubber to my tank a while back because my pH likes to hover in the 7.8-7.9 region. It did its job and raised the pH to between 8.15 and 8.3. I was happy with it an went on with life.

After a while, I noticed that I couldn’t keep up with alkalinity consumption (and calcium) with no corals and minimal coralline algae. I figured out due to severe sand hardening that it was abiotic precipitation. I followed Randy’s instructions several times on stopping the precipitation, including removing the CO2 scrubber. The precipitation would stop and I would slowly bring the levels back up. When they were stable, I would try plugging back in the CO2 scrubber and would immediately come to find the precipitation had begun again.

If I dose, I use sodium bicarbonate (less likely to precipitate than soda ash). I do dose some with a doser when needed, as there is a bit more coralline now, and I have since added a candy cane coral. My magnesium is around 1350 ppm and calcium sits between 420 and 430 ppm.

Unfortunately, my pH stays quite low without the CO2 scrubber, and I definitely want it to be higher, but if the scrubber comes online at all, I can’t keep my arguably more important parameters stable. My tank is 7 months old and has a decent biofilm and algae with several fish, but I still have this issue. The crazy thing is, precipitation in my tank seems to start between 8 and 8.1 pH, which is incredibly low!

Anyone else come across this difficulty with CO2 scrubbers?

 

[doubleshot00]

You trying to keep your PH and alk up but have no corals? Did i read that right?

I have a co2 scrubber and have had nothing but success with it. Actually to much success.

 

[iamacat]

Hey all,

Just wanted to share my experiences and see if anyone else has had this issue. I added a CO2 scrubber to my tank a while back because my pH likes to hover in the 7.8-7.9 region. It did its job and raised the pH to between 8.15 and 8.3. I was happy with it an went on with life.

After a while, I noticed that I couldn’t keep up with alkalinity consumption (and calcium) with no corals and minimal coralline algae. I figured out due to severe sand hardening that it was abiotic precipitation. I followed Randy’s instructions several times on stopping the precipitation, including removing the CO2 scrubber. The precipitation would stop and I would slowly bring the levels back up. When they were stable, I would try plugging back in the CO2 scrubber and would immediately come to find the precipitation had begun again.

If I dose, I use sodium bicarbonate (less likely to precipitate than soda ash). I do dose some with a doser when needed, as there is a bit more coralline now, and I have since added a candy cane coral. My magnesium is around 1350 ppm and calcium sits between 420 and 430 ppm.

Unfortunately, my pH stays quite low without the CO2 scrubber, and I definitely want it to be higher, but if the scrubber comes online at all, I can’t keep my arguably more important parameters stable. My tank is 7 months old and has a decent biofilm and algae with several fish, but I still have this issue. The crazy thing is, precipitation in my tank seems to start between 8 and 8.1 pH, which is incredibly low!

Anyone else come across this difficulty with CO2 scrubbers?

What dKH are you trying to sit at?

 

[Jposch]

Test your phosphate. Not sure why magnesium so highly toted as reducing the abiotic precipitation. Phosphate does a far better job. Below 0.02ppm (nsw level) elevated pH and/or alk are going to be problems. You'll get abiotic precipitation. Even running magnesium as high as 1600ppm, nothing helped like maintaining "elevated" phosphate.
At 0.04ppm, keeping alk at 12dkh and pH at 8.85 is problem free. Yes, Calibrated, functional pH probe and accurate alkalinity testing. Tons of kalk and fresh outside air.

 

[Randy Holmes-Farley]

Hey all,

Just wanted to share my experiences and see if anyone else has had this issue. I added a CO2 scrubber to my tank a while back because my pH likes to hover in the 7.8-7.9 region. It did its job and raised the pH to between 8.15 and 8.3. I was happy with it an went on with life.

After a while, I noticed that I couldn’t keep up with alkalinity consumption (and calcium) with no corals and minimal coralline algae. I figured out due to severe sand hardening that it was abiotic precipitation. I followed Randy’s instructions several times on stopping the precipitation, including removing the CO2 scrubber. The precipitation would stop and I would slowly bring the levels back up. When they were stable, I would try plugging back in the CO2 scrubber and would immediately come to find the precipitation had begun again.

If I dose, I use sodium bicarbonate (less likely to precipitate than soda ash). I do dose some with a doser when needed, as there is a bit more coralline now, and I have since added a candy cane coral. My magnesium is around 1350 ppm and calcium sits between 420 and 430 ppm.

Unfortunately, my pH stays quite low without the CO2 scrubber, and I definitely want it to be higher, but if the scrubber comes online at all, I can’t keep my arguably more important parameters stable. My tank is 7 months old and has a decent biofilm and algae with several fish, but I still have this issue. The crazy thing is, precipitation in my tank seems to start between 8 and 8.1 pH, which is incredibly low!

Anyone else come across this difficulty with CO2 scrubbers?

Where do you see the precipitation?

 

[Trenton Henderson]

You trying to keep your PH and alk up but have no corals? Did i read that right?

I have a co2 scrubber and have had nothing but success with it. Actually to much success.

I started because my alkalinity was always low when my tank first started and I dosed the coralline algae in a bottle, so I wanted it to take off.

What dKH are you trying to sit at?

I’d love 9, but I’ve been trying to get 8 to mitigate precipitation.

Test your phosphate. Not sure why magnesium so highly toted as reducing the abiotic precipitation. Phosphate does a far better job. Below 0.02ppm (nsw level) elevated pH and/or alk are going to be problems. You'll get abiotic precipitation. Even running magnesium as high as 1600ppm, nothing helped like maintaining "elevated" phosphate.
At 0.04ppm, keeping alk at 12dkh and pH at 8.85 is problem free. Yes, Calibrated, functional pH probe and accurate alkalinity testing. Tons of kalk and fresh outside air.

Yeah…last time I checked, phosphate was near zero. This being said, the algae bloom that was eating it up is going away now, so we will see….

Where do you see the precipitation?

Precipitation is nearly entirely to the sand bed. Was rock hard in most of the tank last time I cleaned.

 

[iamacat]

I started because my alkalinity was always low when my tank first started and I dosed the coralline algae in a bottle, so I wanted it to take off.



I’d love 9, but I’ve been trying to get 8 to mitigate precipitation.



Yeah…last time I checked, phosphate was near zero. This being said, the algae bloom that was eating it up is going away now, so we will see….


Precipitation is nearly entirely to the sand bed. Was rock hard in most of the tank last time I cleaned.

That’s a very reasonable and sustainable dKH to shoot for. I am having a hard time grasping why you are dosing anything at all at this stage. You should be more than sufficient with regular water changes to maintain consistent parameters. I believe the issues you are seeing can be linked to the dosing; how it’s mixed, the amount added at once, the area it is added too.

maintaining a consistent water change schedule should resolve your issues and be all you need untill you reach the point your water changes don’t manage the dKH uptake.

 

[SPS2020]

That’s a very reasonable and sustainable dKH to shoot for. I am having a hard time grasping why you are dosing anything at all at this stage. You should be more than sufficient with regular water changes to maintain consistent parameters. I believe the issues you are seeing can be linked to the dosing; how it’s mixed, the amount added at once, the area it is added too.

maintaining a consistent water change schedule should resolve your issues and be all you need untill you reach the point your water changes don’t manage the dKH uptake.

^^ THIS ^^

No reason to dose anything in the first year. Been there, done that, wasted money.

 

[Trenton Henderson]

That’s a very reasonable and sustainable dKH to shoot for. I am having a hard time grasping why you are dosing anything at all at this stage. You should be more than sufficient with regular water changes to maintain consistent parameters. I believe the issues you are seeing can be linked to the dosing; how it’s mixed, the amount added at once, the area it is added too.

maintaining a consistent water change schedule should resolve your issues and be all you need untill you reach the point your water changes don’t manage the dKH uptake.

I do agree with you, but I can’t maintain alkalinity without the supplements. Even with weekly water changes I was seeing significant drops.

Also, an update on the phosphate: 0.02 ppm.

 

[iamacat]

I do agree with you, but I can’t maintain alkalinity without the supplements. Even with weekly water changes I was seeing significant drops.

Also, an update on the phosphate: 0.02 ppm.

Forget the alk and calcium. They don’t matter yet if you are doing regular water changes. You do not have anything up taking them and you have more than enough in any salt mix to grow all the coralline you could imagine while also sustaining a respectable collection of LPS.

what salt do you use? Something here isn’t adding up and it’s either with the salt water or the dosing or both

 

[Trenton Henderson]

Forget the alk and calcium. They don’t matter yet if you are doing regular water changes. You do not have anything up taking them and you have more than enough in any salt mix to grow all the coralline you could imagine while also sustaining a respectable collection of LPS.

what salt do you use? Something here isn’t adding up and it’s either with the salt water or the dosing or both

I use Fritz RPM blue box.

 

[iamacat]

Forget the alk and calcium. They don’t matter yet if you are doing regular water changes. You do not have anything up taking them and you have more than enough in any salt mix to grow all the coralline you could imagine while also sustaining a respectable collection of LPS.


I use Fritz RPM blue box.

Was this sand hardening before your dosing started?

what do you have for flow?

Is it Argonite sand?

sand can begin hardening and sucking out the alk and calcium when parameters get out of whack. I find it unlikely this is related to the co2 scrubber, but is coincidental. If mag gets low the events you are seeing can happen

 

[Trenton Henderson]

I think sand hardening was only a result after dosing. The tank is a 60 gallon long/tall. It’s pretty narrow, though flow at depth is somewhat difficult. I have two MP40’s on Reef crest about 20% I think. Something like 63 x turnover. Magnesium, for the most part, has remained 1350 or higher. I ensure that it is before I use it in my display and check the display regularly.

 

[Trenton Henderson]

Was this sand hardening before your dosing started?

what do you have for flow?

Is it Argonite sand?

sand can begin hardening and sucking out the alk and calcium when parameters get out of whack. I find it unlikely this is related to the co2 scrubber, but is coincidental. If mag gets low the events you are seeing can happen

I think sand hardening was only a result after dosing. The tank is a 60 gallon long/tall. It’s pretty narrow, though flow at depth is somewhat difficult. I have two MP40’s on Reef crest about 20% I think. Something like 63 x turnover. Magnesium, for the most part, has remained 1350 or higher. I ensure that it is before I use it in my display and check the display regularly.

 

[iamacat]

I think sand hardening was only a result after dosing. The tank is a 60 gallon long/tall. It’s pretty narrow, though flow at depth is somewhat difficult. I have two MP40’s on Reef crest about 20% I think. Something like 63 x turnover. Magnesium, for the most part, has remained 1350 or higher. I ensure that it is before I use it in my display and check the display regularly.

I believe your sand started to bind when you dosed to raise the dKH. Alkalinity and calcium became unbalanced and your sand started to uptake leading to precipitate.

if it were me I would run the scrubber. Break up the sand bed. Do a few water changes over the next 2 weeks while regularly stirring the sand bed. Don’t dose anything.

I believe everyone that experiences the sand clumping or hardening only gets there by dosing unevenly

 

[Trenton Henderson]

I believe your sand started to bind when you dosed to raise the dKH. Alkalinity and calcium became unbalanced and your sand started to uptake leading to precipitate.

if it were me I would run the scrubber. Break up the sand bed. Do a few water changes over the next 2 weeks while regularly stirring the sand bed. Don’t dose anything.

I believe everyone that experiences the sand clumping or hardening only gets there by dosing unevenly

I’ll give it a whirl! I guess in some ways, that’s an excuse to grab some corals to have regular consumers in there lol!

Thanks for the in depth discussion. I’ve done SW aquariums before, just not with corals. So testing for those parameters probably made me antsy in the beginning.

 

[iamacat]

I’ll give it a whirl! I guess in some ways, that’s an excuse to grab some corals to have regular consumers in there lol!

Thanks for the in depth discussion. I’ve done SW aquariums before, just not with corals. So testing for those parameters probably made me antsy in the beginning.

I get it man we get excited and want the best for our little water worlds! I have found that I have issues when I get overly involved and 99% of the issues in this hobby are self induced one way or another.

good luck!

 

[Trenton Henderson]

I get it man we get excited and want the best for our little water worlds! I have found that I have issues when I get overly involved and 99% of the issues in this hobby are self induced one way or another.

good luck!

Thanks! Just hooked up the CO2 scrubber and will do a water change in the morning. We shall see…

 

[Trenton Henderson]

Update:

I did about a 15% water change on Friday morning before I left town for the weekend. I left the dosing pumps off and the CO2 scrubber on. I tested this morning (Monday) for alkalinity and calcium and my calcium dropped about 10 ppm to 410 and my alkalinity dropped from about 7 dKH to 5.5 dKH. I don’t think this no dosing thing is sustainable!

 

[doubleshot00]

Update:

I did about a 15% water change on Friday morning before I left town for the weekend. I left the dosing pumps off and the CO2 scrubber on. I tested this morning (Monday) for alkalinity and calcium and my calcium dropped about 10 ppm to 410 and my alkalinity dropped from about 7 dKH to 5.5 dKH. I don’t think this no dosing thing is sustainable!

I don't think your grasping what people are saying above.

You don't have any corals. Its most likely a testing error. If the tank looks ok then quit messing with things.