how to figure how much kalk to dose

[tommy tomato]

I plan on setting up an auto top off with a constant stirring kalk reactor set up on a timer that will dose 8 times a day. I decided to go with the timer route over the float because its cheaper and i feel like the levels of water would be more consistent for dosing kalk... i average about a gallon of water evap a day on about 115g total volume system (i have a lot of fans and no chiller)... i live in south florida, so my evap wont change too much with weather...

a couple questions...

i will be using a 50ml/min dosing pump running at 9 min, 8 times/day. so it will be dosing 450ml of water over 9 minutes, every 3 hours.

would this be too much kalk at once?

the reason its 8 times/day is due to dig timer limitations...

also,

how do you figure how much kalk to use?

is it just by daily calcium consumption of the tank?


sorry if my questions sound dumb.. i am just brainstorming before i go through with buying all the stuff for my ATO..

thanks guys!

 

[HighlandReefer]

i will be using a 50ml/min dosing pump running at 9 min, 8 times/day. so it will be dosing 450ml of water over 9 minutes, every 3 hours.

would this be too much kalk at once?

the reason its 8 times/day is due to dig timer limitations...

also,

how do you figure how much kalk to use?

is it just by daily calcium consumption of the tank?

Per Randy, "Adding 1.25% of the total tank volume with sautrated kalk water will boost pH by an unacceptable 0.6 to 0.7 pH units."

About 0.5 oz (14.8 ml) of saturated kalk will raise one gallon about 0.2 pH units. It is not recommended to raise your tank pH by more than 0.2 pH units.

So for a 115 gallons system, adding more than 1,702 ml. of saturated kalk water at one time would be too much. 450 ml over 9 min. should be ok.

Given that your total water volume is 115 gallons and you have an evaporation rate of about 1 gallon per day, you can add about 1 dKH of alk to your system per day using saturated kalk water. Keep in mind that kalk reactors don't always put out saturated kalk water.

Also, 1 gallon equals about 3785.4118 mls, so you will be short of adding 1 gallon using your dosing schedule by a bit. You will be adding about 3600 mls per day.

 

[tmz]

The dosing rate at 450ml fully saturated limewater for 115 gallons should be fine . You could go a bit higher.
The calcualtion is akward, regretably. There may be an easier math for this but I don't know it.
Generally , 1/4tsp of kalk powder in any given hour per 50 gallons of water volume is ok . So, for 115 gallons you could dose (1/4 x 2.3 or .575 tsps) . At 450ml , the propsed dose is :450 divided by 3875(ml per gallon) or .116x2tsps =.232tsps in a given hour.

Kalk is calcium hydroxide. It adds calcium and alkalinity in proportions balanced to the proportionate uptake in calcification and/or abiotic precipitation of calcium carbonate. So alk and kalk consumption drive the dosing rate.

If you are using a kalk reactor ( neilsen type) you can only dose fully saturated kalk water with it and since you are doing a top off application there is no way I can think of to dose less than full saturation.

Constant stirring is not a good thing. In a sealed reactor it won't degrade the kalk but will keep it stirred up risking a dose of cloudy water containing impurities and more importantly undissolved kalk which can lead to an overdose.

Personally , I prefer a still reservoir( a covered brute garbage can or a covered bucket will do) :strired once when filled;allowed to settle for a few hours, and; dosed via peristaltic pump. The kalk will not loose it's strength for weeks in this set up and only clear kalk water can be dosed. Another advantage is the opportunity to mix in less than 2 tsps per gallon if desired,

 

[tmz]

Hi Cliff,

Posts crossed in the mail.

For clarity the 1/4 tsp max per 50 gallons comes from Sprung and Delbeek, "The Reef Aquarium Vol 3.", a tome which includes many contributions by Dr Farely. The 1/4 tsp per 50g works out to 1114ml of fully saturated kalk water for a 115gallon,which would bump ph by about .13 units, a bit more cautious than .2 with 1702ml.
In any case 450ml is safe and will only boost ph by about .05 units.

 

[HighlandReefer]

Tom,

Yep, 0.2 pH units is pushing it to the max IMHO. If a hobbyist's tank runs at a pH of 8.4, it would push it beyond the 8.5 mark, which is about as high as one would take it. If the tank pH runs at 8.0, then running it up to 8.2 would not be as bad.

 

[tommy tomato]

so this reactor would be no good? http://www.bulkreefsupply.com/store/aquamedic-kalkwasser-stirrer-reactor-1000.html

p.s. you guys are awesome thanks for the help

 

[tommy tomato]

Tom,

Yep, 0.2 pH units is pushing it to the max IMHO. If a hobbyist's tank runs at a pH of 8.4, it would push it beyond the 8.5 mark, which is about as high as one would take it. If the tank pH runs at 8.0, then running it up to 8.2 would not be as bad.

my ph is 8.1

 

[tmz]

That reactor might be fine as reactors go but there is still a risk of cloudy water dosing. Many use reactors and are happy with them. Many have problems with even dosing though. I just don't prefer them and for the $ a pretty good peristaltic or diaphram pump can be had which will do very well with a still reservoir.

 

[tmz]

With ph 8.1 , you should see a jump to 8.15 when the 450ml is dosed and that's not a problem.

 

[HighlandReefer]

I agree with Tom in that kalk reators can produce less than saturated kalk water. If you don't have room for a larger kalk reservoir, than it will do. If, so make sure the reactor is adjusted to produce saturated kalk water. You can check the pH to measure this.

From the directions for use for this kalk reactor it can hold about 1 cup of kalk. Saturated kalk water takes 2 teaspoons per gallon to produce. 1 cup equals 48 teaspoons. So this filled kalk reactor can produce about 24 gallons of satured kalk water and then will need to be refilled with kalk.

 

[tommy tomato]

well my reservoir will be a 14gal dog food storage bin, where i will be holding about 10 gallons of water for my ATO.. because of my ceiling height i am using a BRS dosing pump already for my ATO... so would it be better (and cheaper) to add the kalk right to my reservoir? or do the the two need to be seperate?

 

[HighlandReefer]

Using a still reservoir would be my choice, just add the kalk to it. Make sure you have proper safe guards with your float switch and dosing pump to prevent overdose of kalk water.

 

[tommy tomato]

well im going to put it on a timer, so there wont be any float switch to malfunction.. i suppose the smart thing to do would be to put a safety float switch a bit higher than my water level with a switch to cut power to the pump in the event that the timer malfunctions..

thanks for your help that setup saves me about 240 bucks without a reactor!

 

[HighlandReefer]

You're welcome.

Yes adding extra safeguards is well worth the expense IMHO.

 

[tmz]

You are welcome .
Be sure to turn the dosing pump off for about 2hours after you refill the bin and stir in kalk. Place the input line for the pump 2 inches off the bottom of the bin to avoid sucking up the slurry that will build up there overtime. Keep the bin covered.
I think a safety cut off switch for the pump linked to sump water level sounds like a good idea .

 

[hilton571]

I ran into a product called Kalk King it's a top off and a kalk doser. I've been running this doser for about three months now and am not experiencing any problem. This product comes with a pH probe that allows you to limit how high your PH can go before shut off. This system is a drip system with a float switch. You have three small pumps, one for mixing kalk, one for adding water and one for adding kalk. This might solve your problems, it sure did mine.