2 part precipitation problem solved.

Miller535

Valuable Member
View Badges
Joined
Dec 11, 2019
Messages
2,203
Reaction score
1,939
Location
Pittsburgh, Pennsylvania
Rating - 0%
0   0   0
So I have been having a problem with dosing 2 part and having it precipitate. No matter how much I dosed I could not keep my alk and cal stable, day by day it depleted no matter how much I dosed. I even tried switching from soda ash to sodium bicarbonate. My sand bed was even turning into a giant sheet or rock. Then I watched a old BRS video where they said to dose really slow and that the reason their dosers dose around 1.1ml per min is because the slow dose helped stop precipitation. I use the neptune DOS to dose with. I went and tweaked the dosing so that it dosed no more then 1ml per min. And it did help a lot but it still was precipitating some. I went back and watched the BRS video again and they also mentioned putting a cheap power head under your dosing tubes. So i bought a cheap $35 tunes 500gph ish power head. And it did the trick. 3 days in a row now my alk has been exactly 8.7dkh and my cal 410ppm. I am not posting this to take credit for it, BRS or someone else figured it out. I just thought of I'm having this problem someone else probably is too.
 
I dose my Alk near the outflow of the skimmer. Saved me an extra pump and no extra heat generated.
 
I dose my Alk near the outflow of the skimmer. Saved me an extra pump and no extra heat generated.

I was afraid of the soda ash or alk getting in the skimmer or skimmer pump and building up. And the intake for mu UV is right next to it. And I really didn't want to get anything on the quartz sleeve.
 
As you've noticed, the local mixing where the 2-part solutions are added may be insufficient, and because carbonate/bicarbonate and calcium in reef tanks are already very near maximum saturation, getting the alk in particular to high levels in a small localized environment near the dosing tube will cause calcium carbonate precipitation.

There are several ways to avoid this, one of which you discovered (placing a power head near the addition point). Another way to do it without a power head is to add the alkalinity fairly slowly, and especially, space the corresponding calcium addition out in time and/or space. The Neptune DOS makes this quite easy - you can set the pump to deliver the alk supplement, wait 30 minutes, then deliver the calcium supplement and so on through the day. You can also (by buying an extra tube mount) separate the alk dosing tube from the calcium one. In my case, the alkalinity part is dosed into the main display, which the calcium is dosed into the sump.
 
In terms of high turbulence, here's where I added limewater (right next to the high flow skimmer return) in an attempt to reduce precipitation (still got soemon teh walls, maybe from the drips landing there directly sometimes):

What is that Precipitate in My Reef Aquarium? by Randy Holmes-Farley - Reefkeeping.com

1594474898244.png
 
As you've noticed, the local mixing where the 2-part solutions are added may be insufficient, and because carbonate/bicarbonate and calcium in reef tanks are already very near maximum saturation, getting the alk in particular to high levels in a small localized environment near the dosing tube will cause calcium carbonate precipitation.

There are several ways to avoid this, one of which you discovered (placing a power head near the addition point). Another way to do it without a power head is to add the alkalinity fairly slowly, and especially, space the corresponding calcium addition out in time and/or space. The Neptune DOS makes this quite easy - you can set the pump to deliver the alk supplement, wait 30 minutes, then deliver the calcium supplement and so on through the day. You can also (by buying an extra tube mount) separate the alk dosing tube from the calcium one. In my case, the alkalinity part is dosed into the main display, which the calcium is dosed into the sump.


Both of those are what I did. I dose alk very slowly over about a 15 hour period. And the cal very slowly over about a 9. That alone helped a lot but was not enough to stop the precipitation altogether. So I added the power head.
 
So I have been having a problem with dosing 2 part and having it precipitate. No matter how much I dosed I could not keep my alk and cal stable, day by day it depleted no matter how much I dosed. I even tried switching from soda ash to sodium bicarbonate. My sand bed was even turning into a giant sheet or rock. Then I watched an old BRS video where they said to dose really slow and that the reason their dosers dose around 1.1ml per min is because the slow dose helped stop precipitation. I use the neptune DOS to dose with. I went and tweaked the dosing so that it dosed no more then 1ml per min. And it did help a lot but it still was precipitating some. I went back and watched the BRS video again and they also mentioned putting a cheap power head under your dosing tubes. So i bought a cheap $35 tunes 500gph ish power head. And it did the trick. 3 days in a row now my alk has been exactly 8.7dkh and my cal 410ppm. I am not posting this to take credit for it, BRS or someone else figured it out. I just thought of I'm having this problem someone else probably is too.
Don’t mean to jump on this thread but I’m trying to figure out how to get my dos to configure to the 1 ml per minute. I’m definitely precipitating and can’t dos enough alk to keep it up. I’ve stopped dosing for 48 hours but need to fix my dos as well. Any advice? Trying to get this fixed while the husband is out on deployment.
 
Don’t mean to jump on this thread but I’m trying to figure out how to get my dos to configure to the 1 ml per minute. I’m definitely precipitating and can’t dos enough alk to keep it up. I’ve stopped dosing for 48 hours but need to fix my dos as well. Any advice? Trying to get this fixed while the husband is out on deployment.
You did the right thing by quit dosing for the 48 hours. Now the trick is to start dosing slowly and testing daily for the next few days and see what the consumption rate is.
 
So I have been having a problem with dosing 2 part and having it precipitate. No matter how much I dosed I could not keep my alk and cal stable, day by day it depleted no matter how much I dosed. I even tried switching from soda ash to sodium bicarbonate. My sand bed was even turning into a giant sheet or rock. Then I watched a old BRS video where they said to dose really slow and that the reason their dosers dose around 1.1ml per min is because the slow dose helped stop precipitation. I use the neptune DOS to dose with. I went and tweaked the dosing so that it dosed no more then 1ml per min. And it did help a lot but it still was precipitating some. I went back and watched the BRS video again and they also mentioned putting a cheap power head under your dosing tubes. So i bought a cheap $35 tunes 500gph ish power head. And it did the trick. 3 days in a row now my alk has been exactly 8.7dkh and my cal 410ppm. I am not posting this to take credit for it, BRS or someone else figured it out. I just thought of I'm having this problem someone else probably is too.
How did you get your dos to 1ml per minute?
 
You did the right thing by quit dosing for the 48 hours. Now the trick is to start dosing slowly and testing daily for the next few days and see what the consumption rate is.
I’m worried about all of this though. Currently I’m at 7.5dkh with a heavily stocked mix of lps sps. At what point do I need to worry about it dropping. I probably won’t even make it 24 hours.
 
I’m worried about all of this though. Currently I’m at 7.5dkh with a heavily stocked mix of lps sps. At what point do I need to worry about it dropping. I probably won’t even make it 24 hours.
What alk are you dosing?

You using an Apex trident system to monitor?

@vetteguy53081 maybe you can help this lady out with some sort of idea?
 
I’m worried about all of this though. Currently I’m at 7.5dkh with a heavily stocked mix of lps sps. At what point do I need to worry about it dropping. I probably won’t even make it 24 hours.
Its starting to drop to low point. Assuming your reading is correct, the safest for me was to add soda ash (I used BRS Brand) to the sump. I added in teaspoon increments (diluted) and now steady at 8.87.
 
Last edited:
why not mix with r.o and make a liquid form for a more soluble solution ?
This is mixed- I would not recommend adding straight powder to a sump. Thats a teaspoon diluted and added to sump
 
Don’t mean to jump on this thread but I’m trying to figure out how to get my dos to configure to the 1 ml per minute. I’m definitely precipitating and can’t dos enough alk to keep it up. I’ve stopped dosing for 48 hours but need to fix my dos as well. Any advice? Trying to get this fixed while the husband is out on deployment.
I do not know if it is a dose timing issue, but once precipitation gets going it can be hard to stop. Here's my general advice for such situations:

1. Stop all efforts to boost pH.
2. Stop dosing alk for a bit and let it decline.
3. Reduce pH by switching to a low pH alk mix like sodium bicarbonate, or a calcium organic such as Tropic Marin All for Reef.
4. Ensure magnesium is normal to high.
5. Keep organics and phosphate on the high side.

After a few days of not dosing alk, restart slowly, adding additives to a very high flow area so it mixes in fast.
 
What alk are you dosing?

You using an Apex trident system to monitor?

@vetteguy53081 maybe you can help this lady out with some sort of idea?
Soda ash mixed of course

I use trident (which sucks) cross testing with Hanna (way better)

I think my problem is the dos has it dumping in 9.6ml at a time in the low flow return chamber…ordered a power head but would love to get apex to dose less more frequently (1.1ml/minute theory)
 

IF YOU HAD TO TAKE A REEFING EXAM, WOULD YOU PASS?

  • Yes!

    Votes: 32 45.7%
  • Not yet, but I have one that I want to buy in mind!

    Votes: 9 12.9%
  • No.

    Votes: 26 37.1%
  • Other (please explain).

    Votes: 3 4.3%
Back
Top