Kalk or Soda Ash

paulgriffin971 · Feb 2, 2022

So I have something going on that has probably been discussed before, but there wasn't ever a clear result at the end of the thread(s). Nor was there a simple and exact "this-does-this" or "this is what it does to these parameters" answer for a simpleton like me. BRS tv and the other youtube channels would be cool to do a video on these sort of things, but none to be found unless you piece together several different clips, and still come away confused. Someone HAS to be able to give simple answers for we little folk in the circus

So here goes:
What does Kalkwasser do to parameters and what does it control?
What does Soda Ash do to parameters and what does it control?
What does Sodium Bicarbinate do to parameters and what does it conrtol?
What does 2-part do?
What does a CO2 scrubber/CO2 media do, aside from removing CO2 and slightly raising PH--are there any other affect?
What does a Calcium Reactor control?
What does PH buffer do?
What does Sulfur in a reactor do and control?

My problems, and not trying to get all scientific and such, but I'd just like to see more stability at the mid to higher ranges of my PH and alkalinity. Some people say use kalkwasser in a doser or ATO. Some say use soda ash. Some say use sulfur. Some say use sodium Bicarbinate. Some say use PH buffer--but I tried that and after about 24 hours I'm back from PH 8.3 to 7.8. Some say use two-part, or just one part of the two-part. Some say stick with the CO2 scrubber. And then there's some that say just let it run and leave it alone. But my calcium is always high (600 or more) and my alkalinity is always what I consider low (7). No corraline, and limited growth from my green slimers and montipora. Other "sticks" seem to just to "melt" and die off after a couple months. so, I go searching for answers and there's no simple "this does this" to your parameters. Most is just "use this" and then you go buy the stuff, try it, and find out it doesn't do what you expected to your parameters.

My tank is a reefer 625xxl total system volume is 165 gallons. Apex probes calibrated perfectly--compared with hannah checkers. I don't run any other additives or supplements, just once a month 30 gallon water change with IO reef crystals. I do use a few drops of phosphate RX about every 2 weeks to also help control phosphates between water changes. Other than that, I'm hands off. Did an ICP test a while back right before a monthly water change and the only things that were a little high were phosphate and nitrates: 20 nitrate, 1.0 phosphate. MY RODI water came back with absolutely nothing in it, so that's not the issue.

Temp: 78 night, 79/80 day.
Salinity: 34ppm sometimes dips to 33 or 33.5 when I empty a full skimmer cup
Nitrate: 0.5
Phosphate: 0.32
Alkalinity: 7 to 8 (8 after a water change, 7 after about a week)
Calcium: 600 constantly
Ammonia: 0 (just a normal little bump after feeding anemone)
Nitrites: 0 (just a normal little bump after feeding anemone)
Magnesium: 1400-1460
PH: 7.7 night, peaks at 8 during the day (yes stable, but low in my opinion)

Equipment:
Reefer 625XXL
Red sea reef90 leds--run for 10 hours with 3 hour ramp up/down. 80% max peak.
Corralife skimmer--don't remember the model, but its the big one
BRS GFO/carbon reactor (mainly for phosphates)
Filer socks (for the big chunks)
Dr Tim's biopellets in a reactor (mainly to help with nitrates---but not sure if it does anything really)
Food: Reef Nutrition TDO Chrome Boost pellets in auto feeder, spirolina/brine shrimp frozen morning and night. Feed copeprband clams, and anenome carnivore chunks)

So back to the questions --what does what so I can make the best decision as to what is best to control the parameters I want to? Goal is to raise PH to around 8.3, and get alkalinity to 10/11 stable.

Thanks for the insight \m/

Randy Holmes-Farley · Feb 2, 2022

paulgriffin971 said:
What does Kalkwasser do to parameters and what does it control?
What does Soda Ash do to parameters and what does it control?
What does Sodium Bicarbinate do to parameters and what does it conrtol?
What does 2-part do?
What does a CO2 scrubber/CO2 media do, aside from removing CO2 and slightly raising PH--are there any other affect?
What does a Calcium Reactor control?
What does PH buffer do?
What does Sulfur in a reactor do and control?

Kalkwasser (Limewater in english) adds both calcium and alkalinity and raises pH.

Soda ash adds alkalinity and boosts pH half as much as kalkwasser per unit of alkalinity added.

Sodium bicarboante adds alkalintiy and causes a very small pH lowering.

A two part adds calcium and alkalintiy, may or may not raise pH, and can add other things (see article).

A CO2 scrubber removes CO2 and raises pH. Nothing else directly.

A CaCO3/CO2 reactor adds calcium and alk and maybe other things in the media. It tends to lower pH.

pH buffers are generally some mix of bicarbonate and carbonate. There's nothing special about them that cannot be extrapolated from the ingredients.

A sulfur denitrator consumes nitrate and depletes alkalinity.

This has more:

The Many Methods for Supplementing Calcium and Alkalinity - REEFEDITION

There is no aspect of reef aquarium chemistry more important than calcium and alkalinity. Many of my previous articles have described various aspects of these systems in detail. In reading those articles, aquarists will note one pervasive theme: that maintaining appropriate levels of each are...

www.reefedition.com

Randy Holmes-Farley · Feb 2, 2022

10 to 11 dKH is a high target and will take more effort to maintain in most cases. Did you elect it for a specific reason? Be sure to keep nutrients from getting too low or you may get burnt tips on some fast growing hard corals.

pH can be very hard to dial in without substantial effort. You do not just pick a product and presto, pH 8.3.

paulgriffin971 · Feb 2, 2022

And imagine that, as soon as I wrote this post, BRS comes out with a kalkwasser video today--live! Just can't make it up!

PH and alkalinity are the only two parameters I just can't get figured out what with always having such a very high calcium level in this tank. How to raise alk and PH to the middle of the range without also shooting calcium through the roof. It also seems that 7 alkalinity was the absolute lowest of the acceptable range for a reef system; 12 being highest. My opinion is that there's not much room for error/issues at the bottom or at the top. Shooting for 9/10 alk and 8.2/8.3 PH puts me right in the middle. For safety as well as for growth, balance, etc.

I know every tank is different. My other smaller tanks(a 45 gallon and a 65 gallon) are spot on with where I want to be. No different corals, etc. jsut different fish. It's just the bigger tank giving me this issue. And, I'm not doing anything different between the three tanks.

I know my lighting is perfect, my flow is spot on, and all my other parameters have always been perfectly in check. Just PH, calcium, and alkalinity have always been out of whack. High calcium, low alkalinity, and low(er) PH.

It was starting to seem that kalkwasser was my best choice, but the high calcium level (600) and low alkalinity (7) in my tank concerned me. How to just balance PH and ALK without affecting much else. Now I see that if I go and dose kalk to get my alkalinity and PH up, then my somewhat steady high level of 600ppm calcium will rise even higher. Then I'll start getting Ca precipitant all over my heaters, poweheads, etc. and it could cause me other problems.

Now I'm starting to think soda ash is the way to go---the PH and alkalinity can go up a bit but the calcium will stay where it is. But how to mix and dose when compared to kalk is another challenge. Kalk can go in an ATO, dosing container, or reactor. Soda ash....well....not sure there...have to investigate further.

Or, do I go with Kalk and not worry about the very high Ca since I'll have remedied the PH and ALK issues?

Randy Holmes-Farley · Feb 2, 2022

BRS does provide some good info, but bear in mind they are not chemists, they are sales folks, and I would not rely on their info exclusively.

The article I linked above gives the pros and cons of two parts and kalkwasser. Both are fine ways to go.

Unless you overdosed it, I doubt your calcium is actually 600 ppm. It doe snot just rise on its own.

paulgriffin971 · Feb 3, 2022

Randy Holmes-Farley said:
BRS does provide some good info, but bear in mind they are not chemists, they are sales folks, and I would not rely on their info exclusively.

The article I linked above gives the pros and cons of two parts and kalkwasser. Both are fine ways to go.

Unless you overdosed it, I doubt your calcium is actually 600 ppm. It doe snot just rise on its own.

After reading your article, I think I'm going to try soda ash first and see if I can just get the alk up a bit. That'll probably help the PH like you say. Worried about pushing too much calcium in if I go with Kalk, so will try and focus on one issue first before I try and go with something stronger that could affect other things.

Also read this article you did a while back to help decide:
https://www.reefkeeping.com/issues/2004-09/rhf/#a

And thanks so much--awesome information you help folks with!

ColoredRock · Feb 3, 2022

Randy Holmes-Farley said:
Kalkwasser (Limewater in english) adds both calcium and alkalinity and raises pH.

Soda ash adds alkalinity and boosts pH half as much as kalkwasser per unit of alkalinity added.

Sodium bicarboante adds alkalintiy and causes a very small pH lowering.

A two part adds calcium and alkalintiy, may or may not raise pH, and can add other things (see article).

A CO2 scrubber removes CO2 and raises pH. Nothing else directly.

A CaCO3/CO2 reactor adds calcium and alk and maybe other things in the media. It tends to lower pH.

pH buffers are generallyy some mix of bicarbonate and carbonate. There's nothing special about them that cannot be extrapolted from the ingredients.

A sulfur denitrator consumes nitrate and depletes alkalinity.

Best ever short answer ever.. thank you so much... this should be a graphic on the front page of the sub forum topic.

Randy Holmes-Farley · Feb 4, 2022

paulgriffin971 said:
After reading your article, I think I'm going to try soda ash first and see if I can just get the alk up a bit. That'll probably help the PH like you say. Worried about pushing too much calcium in if I go with Kalk, so will try and focus on one issue first before I try and go with something stronger that could affect other things.

Also read this article you did a while back to help decide:
https://www.reefkeeping.com/issues/2004-09/rhf/#a

And thanks so much--awesome information you help folks with!

You're welcome.

Good luck!

Randy Holmes-Farley · Feb 4, 2022

ColoredRock said:
Best ever short answer ever.. thank you so much... this should be a graphic on the front page of the sub forum topic.

Thanks!

Happy Reefing.

SeeFu · Jul 25, 2023

is there a conversion ratio for replacing soda ash w/ kwalk? I'm using the BRS soda ash and kwalkwasser mixed as recommended by BRS. 2 1/3 cups to 1 gal of water for soda ash and kwalk is mixed to fully saturated.

i'm dosing around 160ml of soda ash/day

Randy Holmes-Farley · Jul 25, 2023

SeeFu said:
is there a conversion ratio for replacing soda ash w/ kwalk? I'm using the BRS soda ash and kwalkwasser mixed as recommended by BRS. 2 1/3 cups to 1 gal of water for soda ash and kwalk is mixed to fully saturated.

i'm dosing around 160ml of soda ash/day

I can tell you the relative potency, but pH changes will change the demand.

In any case, my DIY two part recipe #1 (BRS uses this recipe) is 46.5 times as potent as saturated limewater at 25 deg C.

This calculator is very helpful in this context:

Reef Chemistry Calculator