lime water mixing question

[mflamb]

What is the reason that you want to mix lime water only once when mixed in an open container and then let it settle and not mix it anymore?

[mrpenguin]

ONE of the reasons I know off is because if you dont let the kalk settle on the bottom of your mixing container then that kalk will go settle all over your rock work and corals.

[kgross]

The main reason is CO2. CO2 in the water combines with the kalk to form calcium carbonate. If you keep mixing, more CO2 will get into the water so you will get more calcium carbonate precipitation.

Kim

[mflamb]

Thanks Kim, I knew it had something to do with CO2, but wasn't for sure what.

[Randy Holmes-Farley]

Another issue is that the settled solids can contain many undesirable impurities from the lime or the source water. Things like phosphate, copper, etc. :)

[yraveh]

<a href=showthread.php?s=&postid=14371693#post14371693 target=_blank>Originally posted</a> by Randy Holmes-Farley
Another issue is that the settled solids can contain many undesirable impurities from the lime or the source water. Things like phosphate, copper, etc. :)
I do not understand somethng here. if these solids settle in the top off container, what's the harm of introducing them to the main tank? won't they settle there as well? what will make these solid impurities dissolve in the tank and exert their potentially undesirable effects?

[Randy Holmes-Farley]

They may settle out of pH 12.5 limewater, but could dissolve in pH 8.2 seawater. Copper coats lime particles, for example, but if those lime particles dissolve in the seawater (as they should), the copper may get released.

I show such precipitation of copper here:

The Self Purification of Limewater
http://www.advancedaquarist.com/issues/may2003/chem.htm

[yraveh]

I understand.

[Randy Holmes-Farley]

:thumbsup:

Happy Reefing. :)

[davebehlen]

Has anyone experienced any issues pumping the kalk solution with the Tom's Aqualifter pump? I use one to pump my RO reservoir water, but have always used a filter in front of the pump because I've had a pump get clogged and stop pumping before. I'm pretty sure that was a piece of PVC filing from when I cut and plumbed my system though. I'm thinking the solution would clog the filter, so next I'm wondering if it would clog the pump eventually.

[tmz]

The issue with that pump is it's speed. Kalk needs to be dosed more slowly in most systems.

[Indymann99]

Been running a Toms Aqualifter with Kalk via ATO for 6mo, no problems so far. I mix in the ATO res, let settle for 2hrs, then turn the ATO Pump outlet back on. I like the Aqualifter as it adds ATO/Kalk slow throughout the day.

Aqualifter input tubing (airline) is set at 1in off the bottom of the ATO res (just above the ATO res EMPTY float valve).

http://i300.photobucket.com/albums/nn10/Indymann99/C1E29D97-4D89-49C5-A24F-BF043E70333B_zps6m1rnlhr.jpg (http://s300.photobucket.com/user/Indymann99/media/C1E29D97-4D89-49C5-A24F-BF043E70333B_zps6m1rnlhr.jpg.html)

http://i300.photobucket.com/albums/nn10/Indymann99/6DD142F2-062C-4384-8280-7B1B6FC50083_zpsqvjqpbao.jpg (http://s300.photobucket.com/user/Indymann99/media/6DD142F2-062C-4384-8280-7B1B6FC50083_zpsqvjqpbao.jpg.html)

pH swing nightly
http://i300.photobucket.com/albums/nn10/Indymann99/ApexATOPh_zps603e5d51.jpg (http://s300.photobucket.com/user/Indymann99/media/ApexATOPh_zps603e5d51.jpg.html)

[tmz]

The aqualifer pumps 3.5 gallons per hour per the manufactrues's product description.

This unique vacuum pump is designed to pump water up to 30" at a flow rate of 3 1/2 gallons per hour.

That's much too much kalk at one time. How do you get it to dose throughout the day slowly? I use them for other applications.

[rhdoug]

Well I don't use mine anymore for that due to clogging, BUT when I did I had an electronic timer that came on for a minute or so a few times a day for my nano top-off with kalk. It worked great for a few months. Eventually the pump just became too unreliable for me to use. I suspect it may have been the pre-filter that was the main problem but I'm not really sure. I will eventually install something more reliable like my old bullet-proof litermeter running on my main tank.

[animalkingdom]

I always forget to stir mine after making fresh top off water. I usually have about a 2 inch layer of kalk at the bottom of my top off reservoir. I wonder how much dissolves into solution without stirring? I guess theoretically if I let it sit long enough it will become saturated, but I dont know how long that takes with the lack of surface due to not mixing.

[Indymann99]

The aqualifer pumps 3.5 gallons per hour per the manufactrues's product description.

This unique vacuum pump is designed to pump water up to 30" at a flow rate of 3 1/2 gallons per hour.

That's much too much kalk at one time. How do you get it to dose throughout the day slowly? I use them for other applications.

The Aqualifter capacity doesn't determine how much ATO/kalk goes in, the ATO float switch does... If you look at my APEX chart (red lines = ATO switch ON/OFF) the ATO runs about 6-7 times a day for 2-3min each time (this is about 1g per day). For many this is actually NOT enough kalk being added thus they have to use dosing pumps that can add more than ATO can deliver.

[bertoni]

Depending on the tank, the choice of a dosing area, and the setup used, an AquaLifter might dose more in one shot than is good for the tank. I've heard reports both ways. I used peristaltic pumps, so I have no personal experience with the AquaLifter, though.

[DiscusHeckel]

Depending on the tank, the choice of a dosing area, and the setup used, an AquaLifter might dose more in one shot than is good for the tank. I've heard reports both ways. I used peristaltic pumps, so I have no personal experience with the AquaLifter, though.

Jonathan, how often do you clean your peristaltic pump's head? Does it not get clogged?

[bertoni]

I never had clogging at the pump, but the end of the delivery line got a bit of precipitation. Cleaning it now and then was enough. I don't remember that it ever got plugged.

[tmz]

I also use a peristaltic pump for kalk as top off without clogging over many years of use. I found the aqualifter too fast and too variable in output due to clogging,etc. . I do use them to move some water around in fry tanks.