DIY Kalkwasser Doser


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This is a cool little Kalkwasser doser that works with your top off to dose Kalkwasser (calcium hydroxide). I first saw the idea on RC in the">DIY kalk reactor idea </a>thread. Kudos to [B]JustOneMoreTank[/B] for the great pics and explanation.

Here is a pic of how I setup mine
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The Kalk doser works by pumping RO water through the bottom of small holes in a tube inside the filter. The water rises up through the Kalk and mixes it each time water is pumped through. RO water can be supplied from a top off bucket with a float switch activating a feed pump or from your RO filter with a float valve. This design works best as part of evaporation makeup but could likely be adapted for use with a pH controller for more aggressive dosing on larger reefs. You can also run this system with a continuous drip by gravity feed for a constant supply of calcium.

Here is the parts list and a best estimate on the prices.

Reactor Parts
GE Smartwater Household Filter GXWH20F $30.00

1/4 Pex Pipe $2.00

(2) 3/4 x 1/2 Reducing Bushing MIP $1.30

(2) 1/2 MIP x 1/4 Speed Fitting $5.00

1/4 Inline Valve $6.50

10' 1/4 OD Vinyl tubing $2.00

ATO Parts
JBJ ATO $85.00

Aqua Lifter Pump $10.00

5G Bucket (Free - extra salt bucket will do)

Timer $7.00

Total: $148.80
:photo:">DIY Kalk Doser Video</a> (10.3MB .wmv 1:40)

wow sammy, thanks for that video, really insightfull on how that actually works....time to build one! lol. Do you ever find that you need to shake the kalk bottle or do you not care, lol. And how often do you fill that with new kalk? Thanks.
Sammy33 and JustOneMoreTank...

Gentlemen, Thank you both. This may be the best, easiest, cheapest, thread I have ever read.

I had read the DIY thread on creating a calcium reacter with these filters and had purchased one to do it. But with the CO2 tank and bubbler, it was a lot more complicated and expensive.

This is simply marvelous.

Best possible regards,

Hey no problem everyone. And a big Thank You to Sammy for putting this up. I have just been super busy with work and the holidays and have not been on the computer much when I do make it home. I have a few pictures and would like to try and type out a step by step. There are several options on how you might want to run the "reactor" so it is very customizable depending on how much money you want to spend or what equipment you might already have. I promise to try and get some pictures up sometime kinda soon. :) Happy Reefing and Merry Christmas! :)
We should start a group DIY thread and make this a online project. Great idea.
CGill311 wrote: Why do you need a timer in combination with the ATO? Seems redundant, no?

Dosing the Kalkwasser can raise your pH. The effluent from the doser comes out at around 11 pH. Most tanks naturally dip a bit in pH at night after the lights go out. By using the timer to turn on the ATO/Kalk doser at night you can counter the pH dip with the Kalk additions.

This is optional. You can just run it all day if you would prefer (watch your pH though). It depends on your reef setup. If you have a refugium on reverse lighting it may not matter as much. If you have a high calcium demand then it may be beneficial to dose 24/7.
glxtrix wrote: wow sammy, thanks for that video, really insightfull on how that actually works....time to build one! lol. Do you ever find that you need to shake the kalk bottle or do you not care, lol. And how often do you fill that with new kalk? Thanks.

Thanks for the compliments on the video.

I have heard that the water will channel through after a period of time (weeks I guess) and that the canister needs a good bump to get it started again. This seems to be more common when the Kalk gets low.

Refills are probably at least once a month. I filled this one up with about 3" of Kalk and will probably need to refill when it gets down to 2" or less. The Kalk level has dropped about a 1/4" in almost a week.
Sammy that is a great video!
What container is that for your Kalk solution?
GE Smartwater Household Filter GXWH20F $30.00, as stated in the parts list above, I believe you can get that at HD
Kevin -
You can also use an extra filter canister like you would use on an RO/DI unit for the sediment or carbon block. I got the GE filter and most all the other parts at the big orange box.

The main trick to getting this to work is to run the water through the unit reversed</em> using the output as the input. This way the water will flow down through the tube and through the Kalk and then out through the top.

If you have a larger tank you can also use the big 20" filters. The 10" unit I have works well as my frag tank are only about 75 gallons total. The other cool thing about the GE filter is that it has a bypass valve. The bypass comes in handy if you want to take the Kalk out of the loop and just do top off. This is nice for when I forget to fill my top off bucket or when I refill the Kalk. This gives time to top off the tank while the Kalk settles.
hey sammy, how tall is that filter housing? err, nevermind, just read your post a few up, lol.
I like the idea of runing two of these, first one kalk, and have that run into a carbon/filter block, get a lil more reaction time and that will also make sure that no kalk sediment gets into the tank.
alrighty all, I did a lil searchin for these filter canisters, here is a guy on ebay that is selling the clear ones for a great price!!"></a>

this auction is for 2 canisters, I plan on running another after the kalk which will have a bag-o-carbon, or whatever I feel necessary to put in a misbehaving fish for example, lol j/k.....or am I????? Bwa hahahahahaha. Ok, anyways, you can click on his store and he has all kinds of other housings, ranging from 3/4 inlets to 1/4. I tried searchin for the GE ones, and I'm pretty sure you can buy them at home depot, lowes or whatever hardware store but i liked the bypass idea that they had, then I thought you can still run a bypass on these, just get a Y adapter and have 1/4" valve on the kalk or water line....tadaaa, got your bypass.... I know not as pretty as the GE ones, but it'll work. Hope this helps.">What Your Grandmother Never Told You About Lime</a>
Randy Holmes-Farley (2005)

[IMG]">Calcium hydroxide</a>


[IMG]">The Degradation of Limewater in Air</a>
Randy Holmes-Farley (2003)
Great thread guys and thank you for taking the time to do this. We should create a DIY thread like Sprayin70 recommended.
just a noob question pertaining to doseing kalkwasser.

I once had a float valve stick open because of buildup. Is there someway to prevent this? I was thinking of making an auto-topoff system, or buying one, but I'm wondering if the solnoid is going to get stuck open as well.