Kalkwasser & ATO Use

[ryan c 0_o]

Hey guys, question regarding the interplay between Alk / Calc / Magnesium in the reef tank. Read the articles and still have a little trouble.

The issue I see in my reef tank is a problem maintaining Alk at the 9 ish level. I keep having to use a supplement to raise Alk and have recently starting to use pure baking soda to raise a little.

My question is: is it possible I am using too much kalk mixture to create my auto top off 5 gallon jug? My 55 gallon reef doesn't evaporate too much so I use closer to the 1.5 tsp per gallon mixture of kalk. I do notice some white precipitation around the waterline and also on the heater and pumps. Could the ATO Top Off water bee too high in PH?

I'm confused because if the mixture is too high in PH (meaning over 7) doesnt that mean a basic, not acid environment? The articles as I understand say the Kalk mix creates a higher PH environment with allows for the chemical breakdown of carbon. But higher PH is basic....

Thanks for any input!

Phos = 0
Nitrates = 0
Sal = 1.025
Cal = 520
Alk = 7.9
PH = 8 - 8.1
Mag = 1050

[bertoni]

A higher pH is more basic. Many tanks consume more alkalinity than Kalk is able to supply. My soft coral tanks consumed 2-3 dKH per day for years due to coralline algae growth. How much is the dKH dropping per day?

A little bit of precipitation at the water line or on pump surfaces is normal, but raising the magnesium level to 1275 ppm or so (the canonical ocean average) might help reduce it. I'd get a second opinion on the magnesium kit, if that were easy, before spending much money, though. Test kit problems are reasonably common and 1050 ppm is quite low.

[C.Eymann]

A higher pH is more basic. Many tanks consume more alkalinity than Kalk is able to supply. My soft coral tanks consumed 2-3 dKH per day for years due to coralline algae growth. How much is the dKH dropping per day?



Coraline aside, you would be suprised how much CaCO3 some soft corals use up due to their spicules (CaCO3) in their tissue.

OP, what is the rate you are dripping it at ? are you dripping it ? and are you allowing it to settle before dosing?

The pecipitation you are describing should not be encountered with correctly dosing kalkwasser unless it is dosed in that area, but even then, shouldn't build up very fast, if at all.

like Bertoni said though,
For a smaller volume tank with a higher CaCO3 demand with low evap, will quickly outrun Kalk dosing alone.

[ryan c 0_o]

Thanks for the replies, good info. To be honest, my understanding of the magnesium relationship is only a few months old, so I assume my housekeeping with mag was pretty bad, mostly from water changes.

Also, I've made a change in my routine to let the ATO settle 100 after kalk mixture. I'm wondering if the % mixture is OK and I am just introducing too much calcium by not letting the mix settle.

I have the Osmolator and if the ATO runs out, it dumps a bunch when you reconnect the power. Did not think it was an issue but maybe I am wrong. :/

[C.Eymann]

Thanks for the replies, good info. To be honest, my understanding of the magnesium relationship is only a few months old, so I assume my housekeeping with mag was pretty bad, mostly from water changes.

Also, I've made a change in my routine to let the ATO settle 100 after kalk mixture. I'm wondering if the % mixture is OK and I am just introducing too much calcium by not letting the mix settle.

I have the Osmolator and if the ATO runs out, it dumps a bunch when you reconnect the power. Did not think it was an issue but maybe I am wrong. :/

I have an osmolator as well the intially power up dose of about 1/4-1/2 a cup is no issue unless its super milky kalk.
Also assuming you are mixing kalk in the ato container, is it being mixed? Exposed to air? Pump elevated to prevent dosing parcepitate?
What brand of salt are you using? WC schedule ?

[bertoni]

1 1/2 tsp per gallon is fine for lime. I dosed fully saturated limewater (2 tsp per gallon) for years. I still needed to dose a lot of 2-part.

[ryan c 0_o]

So I use the traditional 5 gallon white plastic jug for my ATO. I drilled a hole in the top to run my Osmolator line and power cord through.

I mix the Kalk with a large plastic rod and then suspend the pump 1/3 from the bottom. The screw cap is not tightened all the way but is rested on the top so not completely exposed to air but not completely sealed either. Some times the Osmolator will suck some of the cloudy mixture if I need to plug it back in. Most of the time its settled when working.

I don't use any premixed salt, I only use the synthetic premium reef salt from the LFS here in Newport Beach, Ca. I typically change 4 gallons of water and clean the sponges in the sump each week.

[ryan c 0_o]

1 1/2 tsp per gallon is fine for lime. I dosed fully saturated limewater (2 tsp per gallon) for years. I still needed to dose a lot of 2-part.

Damn, maybe I my LPS are sucking up the ALK. I think I need to establish the mag to proper levels and let my ATO completely settle. Get better housekeeping in place. Other than that its going ok. Just want better growth and more purple coraline algae.

[C.Eymann]

So I use the traditional 5 gallon white plastic jug for my ATO. I drilled a hole in the top to run my Osmolator line and power cord through.

I mix the Kalk with a large plastic rod and then suspend the pump 1/3 from the bottom. The screw cap is not tightened all the way but is rested on the top so not completely exposed to air but not completely sealed either. Some times the Osmolator will suck some of the cloudy mixture if I need to plug it back in. Most of the time its settled when working.

I don't use any premixed salt, I only use the synthetic premium reef salt from the LFS here in Newport Beach, Ca. I typically change 4 gallons of water and clean the sponges in the sump each week.

Sythetic "premium" reef salt water from a LFS huh? Hmmmm

I have worked in LFS, they will use the absolute cheapest possible salt they can find for premixed SW to sell to customers. If your are doing 4 gal a week with a salt low in alk, could be lending to your problem.

[ryan c 0_o]

1 1/2 tsp per gallon is fine for lime. I dosed fully saturated limewater (2 tsp per gallon) for years. I still needed to dose a lot of 2-part.

Sythetic "premium" reef salt water from a LFS huh? Hmmmm

I have worked in LFS, they will use the absolute cheapest possible salt they can find for premixed SW to sell to customers. If your are doing 4 gal a week with a salt low in alk, could be lending to your problem.

Usually there are 3 options in the LFS around here. RO/DI / Natural Sea Water Usually taken near Catalina Island / or the Synthetic [Premium] option made with the salt combined with the RODI mix.

They say its free from traces of oil or gas or mercury that may be in the Natural Sea Water option. So I usually go Premium mix salt.

[ryan c 0_o]

I'm still confused though on how the Kalk technically works. If the solution is higher in PH, meaning more basic, how does this contribute to the breakdown of calcium in the water?

Wouldn't you need a more acid environment meaning lower PH?

Seems backwards to me for some reason. I'm missing something I think

[C.Eymann]

I'm still confused though on how the Kalk technically works. If the solution is higher in PH, meaning more basic, how does this contribute to the breakdown of calcium in the water?

Wouldn't you need a more acid environment meaning lower PH?

Seems backwards to me for some reason. I'm missing something I think

No, because you are dosing hydroxyl ions and bioavailable calcium (calcium hydroxide) in the same solution, basically both ALK and CAL are delivered in close ratios to consumption via calcification.

If its dosed correctly you shouldn't spike your pH enough to cause ALK/CAL instabilities and resulting precipitation.

[ryan c 0_o]

No, because you are dosing hydroxyl ions and bioavailable calcium (calcium hydroxide) in the same solution, basically both ALK and CAL are delivered in close ratios to consumption via calcification.

If its dosed correctly you shouldn't spike your pH enough to cause ALK/CAL instabilities and resulting precipitation.

So the reaction has already taken place within the ATO reservoir when you mix it? For lack of a better description

And then when the ATO kicks on the bioavailable calcium and hydroxyl are simply added to the tank for consumption by the organism that want them?

And the magnesium helps regulate the process so precipitation is minimized?

That about right??

[bertoni]

The calcium in Kalk doesn't "break down" in water. It simply dissolves as a Ca⁺⁺ ion. Once the Kalk is added to the tank, a lot of the OH^- ions will combine with dissolved carbon dioxide to form carbonates, which corals can use for their skeletons.

Magnesium helps reduce abiotic precipitation by fouling the surfaces of any calcium carbonate crystals that form. The fouling prevents further precipitation. Phosphate will do the same.

[nicholasb]

Looks like the problem is low mag and high cal. Once you get these right, raising alk should be easy. You can maintain your alk anywhere from 7-11. It makes little difference, except faster coral growth at higher D.K.H.

[C.Eymann]

It makes little difference, except faster coral growth at higher D.K.H.

No, corals do not grow faster at higher alk than NSW. This is simply false.

[nicholasb]

No, corals do not grow faster at higher alk than NSW. This is simply false. Why do Red Sea have 2 salt mixes. One with a D.K.H of 7.7, and one with 12 D.K.H. they claim the higher D.K.H gives faster growth.:hmm5:

[C.Eymann]

Why do Red Sea have 2 salt mixes. One with a D.K.H of 7.7, and one with 12 D.K.H. they claim the higher D.K.H gives faster growth.:hmm5:

Because they are expecting those who supplement alk/cal/mag with waterchanges to believe that, and yes its true, the more stable (not higher) your alk, the more rapid growth you will see.
I keep my alk at 8.5 and because I have a Calcium Rx that level never changes, thus I have very rapid growth.

Stability, not high levels. chase stability and not extremes.

[nicholasb]

Because they are expecting those who supplement alk/cal/mag with waterchanges to believe that, and yes its true, the more stable (not higher) your alk, the more rapid growth you will see.
I keep my alk at 8.5 and because I have a Calcium Rx that level never changes, thus I have very rapid growth.

Stability, not high levels. chase stability and not extremes.

According to Randy, studies have shown than some corals calcify faster at higher D.K.H.

[bertoni]

Higher levels of bicarbonate have been shown to increase coral growth. Here are a couple of links:

http://t.tube.aslo.net/lo/toc/vol_44/issue_3/0716.pdf
http://onlinelibrary.wiley.com/doi/10.4319/lo.1999.44.3.0716/full

How much extra growth any tank might show would depend on a number of factors, including other limiting factors to growth, such as nutrients and light.

[C.Eymann]

According to Randy, studies have shown than some corals calcify faster at higher D.K.H.

While he provides some great articles, I don't agree with everything Randy Holmes Farley says.

One incidence I proved him wrong on evap vs kalkwasser use and demand.
I won't link as it was super old, forgotten password account, but I did.


Does he have a thriving SPS tank? No?


When trying to get a balance of color and growth it has been found that stable alk of 7-9 provides ideal results in not just growth but color as well, esp when combined with a low nutrient system

I see no reason why increasing alk would directly increase growth rate, pH yes, having higher pH levels allows calcification to happen more readily and rapidly.
BUT has nothing to to do with higher alk= faster growth. thats a farce IMO.

[bertoni]

Higher pH and higher alkalinity have similar effects at making calcification happen more readily. The linked articles go into some detail. Both increase the supersaturation.

[ryan c 0_o]

Thanks for the info everyone. I ran out and got some AquaVitro Mag and Reef Fuel and a new Mag test kit.

I disconnected my ATO and Kalk to let the Calcium come down and supplemented a little baking soda to stabilize the Alk.

I'm not gonna introduce anymore kalk unless its all cleared and settled. I think last time I did a water change the ATO dumped a little too much in. Personal error. But keeping the mag at the correct level I think will help in the future.

The kalk dissolving instead of breaking down makes a little more sense to me. Maybe my system was pulling too much alk because of precipitation, hopefully the mag will solve this!

Thanks again!

[bertoni]

You're welcome. I think raising the magnesium should reduce the abiotic precipitation, and I'd definitely give it a shot.