Dosing Kalk and hand dosing Alk

[Instigate]

So I've been dosing 6 tsp of kalk in my 5 gallon ato res for a while now and I keep noticing the alk needing a boost but the calcium stays fine with the current dosage of kalk. So I have been adding Alk(Soda Ash Liquid) and it bumps it back up for a day or two then drops back down. I'm targeting 9 DKH and it keeps dropping to 8 DKH. Would it be better to raise the amount of kalk to keep the alk up? Or should I keep doing like I am?

 

[sghera64]

So I've been dosing 6 tsp of kalk in my 5 gallon ato res for a while now and I keep noticing the alk needing a boost but the calcium stays fine with the current dosage of kalk. So I have been adding Alk(Soda Ash Liquid) and it bumps it back up for a day or two then drops back down. I'm targeting 9 DKH and it keeps dropping to 8 DKH. Would it be better to raise the amount of kalk to keep the alk up? Or should I keep doing like I am?

What is your tank pH?

It might be possible that over additions of kalk might precipitate alk out of the water. Do your pumps and heater have much calcium carbonate on them?

 

[Instigate]

What is your tank pH?

It might be possible that over additions of kalk might precipitate alk out of the water. Do your pumps and heater have much calcium carbonate on them?

pH is 8.4. Been stable there. No buildup on the equipment. The tank seemed to be uptaking equal amounts for about a month I think then alk started to need supplementation. But I'm starting to get a lot of coraline algae now. Tank has been up for 9 months but only has 14 or so small frags and a good size trachy. I was getting good growth for several months from everything but my not calibrating my refractometer led to a salinity drop and only my stunner chalice is really growing now. I got parameters back on track and everything has been stable now for a couple months I think.

 

[Randy Holmes-Farley Verified Community Expert]

It all sounds normal to me. Dropping alk is always the first sign of underdosing calcium and alk.

I’d first try saturating the limewater with calcium hydroxide by going to 10 teaspoons.

If that fails to maintain alk, then using a two part in addition or instead of the limewater would be a good plan.

 

[Instigate]

It all sounds normal to me. Dropping alk is always the first sign of underdosing calcium and alk.

I’d first try saturating the limewater with calcium hydroxide by going to 10 teaspoons.

If that fails to maintain alk, then using a two part in addition or instead of the limewater would be a good plan.

Thanks for the guidance!

 

[Randy Holmes-Farley Verified Community Expert]

You’re welcome. Good luck!

 

[vikinglord13]

What are your magnesium levels at Joe? It's important to ensure those levels are good to go as well.

 

[Instigate]

What are your magnesium levels at Joe? It's important to ensure those levels are good to go as well.

I'm at 1395ppm right now. Magnesium and calcium have been very stable with the kalk but the alkalinity is dropping 1dkh a day while I've got kalk in the ATO. But it hasn't been evaporating as much lately. Thinking about setting up a kalk drip instead of in the ATO.

Cal - 450 ppm
Alk - 8-9 DKH Daily
Mag - 1395 ppm
SG - 1.025
pH - 8.4
NO3 - 1ppm
PO4 - .1ppm

 

[Randy Holmes-Farley Verified Community Expert]

I'm at 1395ppm right now. Magnesium and calcium have been very stable with the kalk but the alkalinity is dropping 1dkh a day while I've got kalk in the ATO. But it hasn't been evaporating as much lately. Thinking about setting up a kalk drip instead of in the ATO.

Cal - 450 ppm
Alk - 8-9 DKH Daily
Mag - 1395 ppm
SG - 1.025
pH - 8.4
NO3 - 1ppm
PO4 - .1ppm

The problem is the water level will rise.

If you like the pH boost of limewater but cannot dose enough due to limited evaporation, you might try one of my newer DIY two part systems using sodium hydroxide which has no dosing limitations as limewater/kalkwasser does:

https://www.reef2reef.com/threads/second-new-diy-two-part-recipe-with-higher-ph-boost.357080/

 

[Instigate]

The problem is the water level will rise.

If you like the pH boost of limewater but cannot dose enough due to limited evaporation, you might try one of my newer DIY two part systems using sodium hydroxide which has no dosing limitations as limewater/kalkwasser does:

https://www.reef2reef.com/threads/second-new-diy-two-part-recipe-with-higher-ph-boost.357080/

I'll have to check that out.

 

[Instigate]

OK so I think I figured out my issue. Tonight I had to reach in and clean algae(bryopsis, treating with fluconazole) off a dead fungia plate that has a bunch of babies growing on it and when I set it back down I felt the sand. It has an upper layer that is hard but brittle, that would be the precipitation we were looking for right? I believe it was due to my hard line tube sticking down to low in my ATO bucket and sucking up some of the slurry at the bottom which created a precipitation problem where I'm adding more and more kalk and alk.

So to fix it I would shorten the hard line and go back to 5tsp of kalk in my 5 gallon ATO reservoir? Then should I continue to monitor alk twice daily and add alk liquid as needed till it doesn't need it or would that just continue the problem? Should I break up the crusty sand? Remove it? Leave it?

 

[Randy Holmes-Farley Verified Community Expert]

Sand hardening is one way that precipitation appears to show up, but every tank has some precipitation (like on heaters and pumps), but it often goes unnoticed.

It is not unusual for sand to harden, especially when it is new. here's my standard comment on it:

Clumping of sand may be purely abiotic, but may also be driven by biological processes, and most often happens with new sand.
Reduced precipitation can be reached with lower pH, alkalinity and to a smaller extent, calcium, and higher magnesium, organics, and phosphate.

Fresh CaCO3 surfaces can be most prone to more precipitation. To break the cycle, it can be useful to stop dosing for a few days, let alk fall and precipitation stop, then restart with a much lower dose, maybe using a lower pH product.

 

[Instigate]

Sand hardening is one way that precipitation appears to show up, but every tank has some precipitation (like on heaters and pumps), but it often goes unnoticed.

It is not unusual for sand to harden, especially when it is new. here's my standard comment on it:

Clumping of sand may be purely abiotic, but may also be driven by biological processes, and most often happens with new sand.
Reduced precipitation can be reached with lower pH, alkalinity and to a smaller extent, calcium, and higher magnesium, organics, and phosphate.

Fresh CaCO3 surfaces can be most prone to more precipitation. To break the cycle, it can be useful to stop dosing for a few days, let alk fall and precipitation stop, then restart with a much lower dose, maybe using a lower pH product.

The precipitation wont stop if I shorten the hard line and switch back down to just 5tsp of kalk in the ato? Stopping dosing is the only way to stop the precipitation? I wouldn't be able to just taper down slowly? I'm afraid stopping dosing would let my alk swing too low. How much of a swing can the corals tolerate? I mainly have LPS with a few zoas. Should I break up the crusty sand? Remove it? Leave it? Doesn't mater?

I stopped the kalk and I'm now just hand dosing, testing alk twice a day and calcium once. Targeting 8dkh now. Been doing 45ml of soda ash liquid twice a day to keep it at 8dkh. Before I was letting the ATO top off with 10tsp of kalk and was dosing 100ml once a day to keep it at 9.

 

[Randy Holmes-Farley Verified Community Expert]

The precipitation wont stop if I shorten the hard line and switch back down to just 5tsp of kalk in the ato? Stopping dosing is the only way to stop the precipitation? I wouldn't be able to just taper down slowly? I'm afraid stopping dosing would let my alk swing too low. How much of a swing can the corals tolerate? I mainly have LPS with a few zoas. Should I break up the crusty sand? Remove it? Leave it? Doesn't mater?

I stopped the kalk and I'm now just hand dosing, testing alk twice a day and calcium once. Targeting 8dkh now. Been doing 45ml of soda ash liquid twice a day to keep it at 8dkh. Before I was letting the ATO top off with 10tsp of kalk and was dosing 100ml once a day to keep it at 9.

I don't know if it will stop just be reducing the dose, but it might. Some folks get into cycles where dosing takes more and more to maintain alkalinity, far above normal dose levels. Switching to baking soda instead of soda ash will also help by reducing the pH.

The reason is that fresh calcium carbonate surfaces are a huge driver of additional precipitation on top of them. It's a positive feedback loop that can be hard to break.

 

[Instigate]

I don't know if it will stop just be reducing the dose, but it might. Some folks get into cycles where dosing takes more and more to maintain alkalinity, far above normal dose levels. Switching to baking soda instead of soda ash will also help by reducing the pH.

The reason is that fresh calcium carbonate surfaces are a huge driver of additional precipitation on top of them. It's a positive feedback loop that can be hard to break.

Got an update for you. I seem to be lucking out, I've been closely monitoring alk and dosing less and less while trying to maintain alk at around 8DKH and it seems to be working. I'm down from 10tsp kalk in 5 gallon ato plus 100ml of liquid soda ash daily to just two 15ml doses of liquid soda ash a day. Yesterday I was at 2 18.5ml doses and today down to 15ml. Calcium and magnesium are holding steady.

 

[Randy Holmes-Farley Verified Community Expert]

Sounds good.

 

[Instigate]

I've been slowly reducing the alk dosing to try to ease the system down to stop precipitation. I got down to 7.6DKH and 415ppm CA, and stopped dosing for the past 4 days:
5-28-28
4:20PM 7.6DKH ALK
Dosed 18ml Liquid Soda Ash
8:30PM 7.6DKH ALK / 415ppm CA / 1465ppm Mg (IO salt and I just did a WC the previous week)
Dosed 37 ml Liquid Soda Ash / 66.5ml Calcium Chloride (Trying to get back up to 8DKH and 420ppm CA)

8:30PM
5-29-18
10:00AM 7.6DKH ALK
10:00PM 7.6DKH ALK / 430ppm CA

5-30-18
11:00AM 7.3DKH ALK
8:00PM 7.3DKH ALK / 430ppm CA

5-31-18
1:00PM 7.0DKH ALK
8:00PM 7.0DKH ALK / 425ppm CA

6-1-18
12:00PM 7.0DKH ALK / 425ppm CA
11:00PM 6.85DKH ALK / 425ppm CA


Thinking about just dosing 15ml every day and see if it stables out or maybe start 1/2tsp of kalk per gallon in the ato. I'm afraid to let it drop below 7. Does this sound like an acceptable plan? Or it's still precipitating so I should just let it drop? I guess I'll do nothing tonight and test again in the morning, maybe resume dosing then.

 

[Randy Holmes-Farley Verified Community Expert]

Switching to baking soda for the alk part may reduce precipitation more, if that's the goal.