Kalkwasser Mixing Question

[rleechb]

I am a lazy, lazy man. I've been mixing kalkwasser by putting a few tablespoons of the powder into a 5 gallon bucket, filling it with RO/DI, mixing, and then letting it sit overnight to settle. Then I siphon the clear portion of the fluid into my 22 gallon reservoir. It's getting a bit irritating, as I have to mix kalk close to every day, and I'd rather not do it.

I'm currently dosing with a peristaltic pump on a slow drip. My question is... can I just make a "fake" kalk reactor with reservoir? I was thinking about putting a modded maxijet into my reservoir, and having it on a timer to turn on/off a few times a day to mix. I'd just dump a cup or two of kalk into the water whenever it seems low, and keep the reservoir nice and full by topping it off with RO/DI?

Any drawbacks to this?

 

[theatrus]

Yeah that would be fine. The trick with kalk reactors is to get the air out of them and don't let any new air in. I used a 4" diameter section of PVC, drilled a few holes and attach hose nipples, and use a MJ400 on a timer to 'stir" the mix.

 

[rleechb]

yeah, i remember reading an article by Randy about how kalk doesn't degrade much in a reservoir as long as the lid is on. I figure as long as I keep the lid firmly on, and top off the reservoir fairly seldomly (maybe once every 4-5 days).. voila! Cheap "reactor".

 

[theatrus]

Yup, the enemy of kalk is CO2. So the tighter you can get that lid to fit and the less air you introduce by servicing it the better.

 

[rleechb]

what exactly happens to kalk when co2 is introduced? Does it precipitate something harmful to the water, or something inert that doesn't threaten the reef?

 

[shinny]

I would like to see a picture of what you built theatrus. If ya got any pics that would be great.

 

[KDodds]

Have you considered a Kalk stirrer (AKA Nilsen Reactor) on a top-off switch?

 

[rleechb]

I have a peristaltic right now that's working quite well. I don't really trust float switches at all; way too many nightmare stories with them. I'm considering a kalk reactor, but i'm a bit strapped for space around the tank. I already have a fairly large reservoir sitting in my living room covered in a blanket, and my calcium reactor takes up nearly all the space under the cabinet.

If I keep the lid on tight, minimizing co2 introduction into the reservoir, what would be the benefit of adding a kalk reactor?


Also... how would I even hook up a kalk reactor w/ my existing peristaltic? Would I need another pump to feed the reactor, and the peristaltic to draw water out of the reactor and into the tank?

 

[theatrus]

Not sure how you would pull it off with dosing pumps. And I don't have a picture handy - its pretty ugly imo I run mine on my autotopoff with two float switches, managed by my AC Jr. In effect I now have triple redundancy:
- Main float
- Second float
- Can't dose too much at once as ATO shuts off when pH > 8.25 (and pH goes up fast)

 

[bklynmet]

you'd want to not disturb the surface 'crud' so the lime won't precipitate out...

I'll be making a DIY kalk reactor with a fellow reefer tomorrow and we'll be posting photos afterwards in the DIY forum... it's supossedly really simple and can be done without hurting the wallet... so keep an eye out for it in two days or so.

 

[funkyman]

How soon after stirring the kalk can you start dosing from it?

 

[Johnbob]

The ionized calcium reacts with the CO2 in the air to form calcium carbonates which you should have plenty of already in your system. Calcium carbonate has a very low solubility and at alkaline pH, it is even less...thus, the precipitate that forms when making kalkwasser. For that matter, the lime is not that soluble in water either, so the danger lies in the atmospheric CO2 causing a substantial proportion of the ionized calcium to be lost when the calcium carbonate forms and precipitates thereby foiling your efforts to raise free calcium in your system. Although it is usually not recommended, I have taken to dosing my kalkwasser immediately upon mixing with good results. I just add a tablespoon of lime to a gallon of DI/RO water, mix it, and then let it drip in at night to replace my evaporative loss. As it drips, most of the insoluble lime settles out anyway, so very little of the undissolved lime makes its way into the system.

 

[RichConley]

<a href=showthread.php?s=&postid=8038574#post8038574 target=_blank>Originally posted</a> by rleechb


Also... how would I even hook up a kalk reactor w/ my existing peristaltic? Would I need another pump to feed the reactor, and the peristaltic to draw water out of the reactor and into the tank?

Just use the peristaltic to push RODI into the reactor. Limewater will come out of hte reactor at the same rate you push RODI in .