Kalk dosing in ATO

[vanisher]

So I'm considering starting to dose kalk using my ATO.

I don't have a large system (yet, new tank coming), but I was wondering how I would set this up so I don't overdose my tank.

I have a 12 gal aquapod and a 5 gal semi-sealed jug of fresh ro/di water for top off.

I don't have a large load of alk/calc consumption yet either, again planning ahead here.

So for the ATO, I go through 90% of the jug in ~3-4 weeks.

My question is is there a simple formula to follow for this? I'm not sure where to start.

Thanks in advance!

 

[theplatypus]

1-2 tspn per gallon of water

 

[chris31]

Can you dose Kali directly to the display tank instead of buying something that does it for you?

 

[Randy Holmes-Farley]

I'd start at 1 tsp per gallon of top off added very slowly. How fast does your ATO add water?

Can you dose Kali directly to the display tank instead of buying something that does it for you?


Yes, but you'll have to manually add it several/many times per day to avoid excessive pH spikes. Most people at least opt for a DIY drip line.

This has more:

What Your Grandmother Never Told You About Lime
http://reefkeeping.com/issues/2005-01/rhf/index.htm

 

[vanisher]

I'd start at 1 tsp per gallon of top off added very slowly. How fast does your ATO add water?

Can you dose Kali directly to the display tank instead of buying something that does it for you?


Yes, but you'll have to manually add it several/many times per day to avoid excessive pH spikes. Most people at least opt for a DIY drip line.

This has more:

What Your Grandmother Never Told You About Lime
http://reefkeeping.com/issues/2005-01/rhf/index.htm

First of all, thank you for your replies.

I use a tom's aqua lifter and it states 3.5 gal per hour.. that comes to ~220 ML per minute.

I guess my worry is that if I'm not using enough alk/calc in the system and topping off with the kalk is going to vary on my evaporation rates.

How do you guys combat that?

 

[tmz]

At the rate of 3.5 gallons per hour for a 12 gallon tank you may be adding all of your daily top off at once( somewhere around 684 ml for a 12 gallon tank with an evaporation rate of1.5% of tank volume per day or about 28 days for your 5 gallon top off reservoir) ) This would be too much kalk at one time. To avoid ph spikes limiting the amount of kalk dosed in a given hour for the 12 gallon should be around 115 ml of kalk water mixed at two tsps per gallon.Using less than 2tsps per gallon will increase the amount of solution that can be dosed at one time but will also limit the amount of kalk dosed as top off.. So your daily top off if a 2 tsp per galon mix is used should be spread over at least 5 or 6 hours . The smaller the increments the better with even dosing over 24 hours being optimal to avoid dosing too much kalk at once and to also maintain consistent sg. The aqualifter may not be a precise enough dosing pump for your application unless you have another means( float witches etc) of incrementalizing the top off to a maximum 115 ml at at a time.

 

[tmz]

Varitions in evaporation rates will obiously effect the daily kalk dose but they may not vary wildly enough to make a bifdifference.

FWIW, I dose kalkwasser from a still reservoir at a preset amount per day to match top off needs. . It is delivered in 150 increments over 24 hours via a litermeter 3 perstaltic pump. Evaporation is pretty constant in my system but I make up for any occasional or seasonal evaporation that exceeds the preset dose by adding some ro/di water to the sump.

 

[mikecc67548]

12 gallon you better do it pretty slow

 

[skunkmere]

i got a 20g DT w/ about 20g sump. i use 1 tsp mix in my 5g water ATO res. it holds at 8-9 dkh. tank hold lps. acans, blastos ect.

 

[vanisher]

At the rate of 3.5 gallons per hour for a 12 gallon tank you may be adding all of your daily top off at once( somewhere around 684 ml for a 12 gallon tank with an evaporation rate of1.5% of tank volume per day or about 28 days for your 5 gallon top off reservoir) ) This would be too much kalk at one time. To avoid ph spikes limiting the amount of kalk dosed in a given hour for the 12 gallon should be around 115 ml of kalk water mixed at two tsps per gallon.Using less than 2tsps per gallon will increase the amount of solution that can be dosed at one time but will also limit the amount of kalk dosed as top off.. So your daily top off if a 2 tsp per galon mix is used should be spread over at least 5 or 6 hours . The smaller the increments the better with even dosing over 24 hours being optimal to avoid dosing too much kalk at once and to also maintain consistent sg. The aqualifter may not be a precise enough dosing pump for your application unless you have another means( float witches etc) of incrementalizing the top off to a maximum 115 ml at at a time.

I don't think I mentioned that the aqualifter is activated by a float switch. It's not topping off on a schedule, only when the switch kicks on.

 

[Randy Holmes-Farley]

I guess my worry is that if I'm not using enough alk/calc in the system and topping off with the kalk is going to vary on my evaporation rates.

How do you guys combat that?

There is a negative feedback loop that prevents such issues from being a big deal, IMO.

As the alk rises and the pH rises, demand in the tank for calcium and alkalinity also rises, offsetting additional inputs. The opposite happens as alk declines, and demand almost disappears as alk drops to 6 dKH or so.

You may want to change the concentration of limewater with big seasonal differences in evaporation, but day to day it is not a concern, IMO.

The aqualifter might be a bit fast, but some folks use it. How much gets added with each triggering of the float switch? That's the big question.

 

[vanisher]

I guess my worry is that if I'm not using enough alk/calc in the system and topping off with the kalk is going to vary on my evaporation rates.

How do you guys combat that?

There is a negative feedback loop that prevents such issues from being a big deal, IMO.

As the alk rises and the pH rises, demand in the tank for calcium and alkalinity also rises, offsetting additional inputs. The opposite happens as alk declines, and demand almost disappears as alk drops to 6 dKH or so.

You may want to change the concentration of limewater with big seasonal differences in evaporation, but day to day it is not a concern, IMO.

The aqualifter might be a bit fast, but some folks use it. How much gets added with each triggering of the float switch? That's the big question.

Ok, that's some good info to know.

As far as the aqua lifter being fast, it's on for an average of 30 seconds per triggering (I counted a few times today since I figured that question would come up).

It dribbles into to the tank, maybe 2 drops per second? Do you think that would be too much if I started with say 1.5 tsp per 5 gal ato fill?

 

[Randy Holmes-Farley]

That sounds OK. Adding 1.25 % of the tank volume will boost pH instantly by about 0.7 pH units, so that's too much. Half that is borderline. A tenth that is fine.

 

[vanisher]

That sounds OK. Adding 1.25 % of the tank volume will boost pH instantly by about 0.7 pH units, so that's too much. Half that is borderline. A tenth that is fine.

Great!

Thank you and everyone else who commented for the help, it is much appreciated.

I will give it a try today since I have to refill the ato jug again anyway.

I'll monitor alk/calc/ph closely over the next few days and report back. :beer:

 

[Randy Holmes-Farley]

:thumbsup:

Good luck.

 

[glennhornibrook]

sorry for adding my own question to this thread but it is in relation to the link above '' what grandmother didn't tell you about lime''

I noticed it suggests when using a kalk reactor with stirrer that you only mix intermittently through the day.

My DIY stirrer is variable speed adjusted so the heavy milky material rises about 3/4 way up stirrer and limewater is taken from the top.
The stirrer runs continuously .
Is this ok ?

 

[Randy Holmes-Farley]

As long as the milky llimewater does not escape, that is fine. At the time of writing that article, most reactors did not have the design you have.

 

[glennhornibrook]

Just to clarify, when people talk about calcium hydroxide they tend to talk about a clear solution and a milky solution.
This discription is a little bit confusing for me.

When using it I find that you get a clear solution which looks like water but you also get two layers of milky solution.
One layer looks like full fat cows milk.
The other layer looks like a pint of water with a tea spoon of milk in it ( as in the photo of the reactor in the above article)

I have been using the latter as I haven't had much worth from using the clear solution.

Is what I am doing a problem?

I would love some clarity on the above please. ( pardon the pun )

 

[Randy Holmes-Farley]

Not sure what you mean by the different layers. Limewater itself is clear.

If you let it sit around but covered for a day or longer, it will settle out with solids/mud on the bottom, maybe a crust of calcium carbonate on the top of the water, and clear limewater in between. How long that takes may depend on the particle size of the starting calcium hydroxide, smaller particles settling more slowly.

If CO2 from the air can access it from the top, then you may continue to get calcium carbonate forming through it over time, and it may not become clear for a very long time.

In general, it is best to add the clear liquid. Milky limewater can contain very high and variable amounts of solid particles which can drive the pH super high if too much is added. The clear liquid also avoids some impurities that are likely to be in the mud on the bottom, including copper, phosphate etc.

This has more on what solids are what in limewater dosing:

What is that Precipitate in My Reef Aquarium?
http://reefkeeping.com/issues/2005-07/rhf/index.htm

 

[glennhornibrook]

Firstly thanks for your replies.

When I add calcium hydroxide to my reactor, above and beyond saturation amount eg. 7oz to 0.26 gallon reactor and throttle back the stirrer a definate division appears about half way down the container.
The bottom of the container forms a thick white sludge and above that forms a less dense milky solution. ( get a pint of water and add 1 tea spoon of milk to see what I mean. Also it can be seen in " what grandmother didn't tell you about lime".)

If the stirrer is throttled back further a clear solution appears at the top which apparently is the usable part.
The problem is that this clear solution doesn't seem to fulfill my calc and alk needs.( I am dosing 24ml of vinigar to the reactor daily)

The only way that does work for me is if I add 1 oz daily and stirr at full speed. (adding full contents of container with dripper and timer )
This is dripped into a high flow area of the sump.
This is not practical though for example if I need to go away for a week.
Also it is not ideal for reasons outlined in the links you provided.( I monitor PH daily )

If the stirrer is turned off it settles as you described but that is not the intended purpose of the reactor.

I find that the solution in the reactor changes after a day or two and insdead of the 3 layers as I described you get a clearer but not crystal clear solution with what looks like a snow storm floating around in it.

Is the clearish part of this solution good to use?

Is the snow storm just undissolved calcium hydroxide ? ( The reactor is sealed and no air gets in with RO water )

You say you let it settle in a container. Do you use all the clear solution and then add more RO water and mix again.?

Am I right in saying that the sludge will not desolve without being stirred?

Sorry for all the questions but I have read alot of articles on kalkwasser but I still haven't quite got the hand of it.