Kalk newbie...

bsfmaximus · Aug 18, 2017

I decided to take the plunge and switch from two part to kalkwasser today. I'm looking for input, advice, and/or validation…

I setup a jebao DP4 dosing pump today with the intention to dose kalk. I mixed my first batch of kalkwasser using one teaspoon per gallon of RODI water. The middle of the solution cleared, bottom has sediment, top has film. My airline tube is about an inch from the bottom of my container.

I have set up the dosing pump to dose 10ml of the kalk solution once an hour, every hour of the day. The kalk is going into a high flow area of my display tank, I don't have a sump. I have a 54 gallon tank with a HOB skimmer and canister filter.

My burning question- is 10ml of kalk solution given at once safe? Could I dose more at one time? What if I need to bump up to 2 tsp kalk per gallon? I don't want to harm any coral. My doser does not have any sort of option to slowly drip any given amount, It can only give a designated amount once per hour. If need be, I could use two channels for the same bucket of kalk to dose less volume more times per hour.

Any input is greatly appreciated!

Randy Holmes-Farley · Aug 19, 2017

10 mL at once is fine, and the overall dose you are using is very small.

You are dosing less than 0.2 dKH per day total even if you used 2 tsp lime per gallon of fresh water.

bsfmaximus · Aug 19, 2017

Randy Holmes-Farley said:
10 mL at once is fine, and the overall dose you are using is very small.

You are dosing less than 0.2 dKH per day total even if you used 2 tsp lime per gallon of fresh water.

Thanks, Randy. I was hoping you'd weigh in. I gathered that I would be low from reading your past write ups.
I'm fearful to up my dose because the question that I couldn't find an answer for is specifically how much I could add at a given time without danger of hurting my lps or sps or tank inhabitants. My doser pumps out my dose all at once each hour, drops fall into the water maybe two per second.

bsfmaximus · Aug 19, 2017

I don't know if I am over complicating this. I'm worried if I set my doser to give a larger amount that it will be too much at once. I'm presently trying to find something that could collect the full volume of the dose and then slowly drip it until the next dose is pumped.

Randy Holmes-Farley · Aug 19, 2017

If it mixes in fairly well before hitting a coral, you can add a lot more.

The concern is elevated pH, and adding 1.25% of the tank volume using saturated limewater at once will boost something like 0.7 pH units. That's way too much at once, but 0.1% is likely OK, and o.o5% gives a buffer against not fully mixing. That's about 100 mL per dose for you.

But starting slower and monitoring alkalinity is a good way to go.

bsfmaximus · Aug 19, 2017

Watching the kalk enter my tank, I see it create a film on my surface until that hits a turbulent area, then it dissipates into the tank. Is that to be expected?
Thanks to your explanation, I feel much better about the volume to add… I will pump it up and gradually start increasing until I find stability.

Randy Holmes-Farley · Aug 19, 2017

It forms magnesium hydroxide solids on entry to the water, and that will redissolve if it is not allowed to sit too log.

bsfmaximus · Aug 19, 2017

Great. 10ml dissolves into the water within a few seconds. Hopefully the same with 100ml. Thank you, Randy!!!

jtl · Aug 20, 2017

I have a similar question. I am getting ready to dose Kalk using an Aqualifter pump from my top off container. My total water volume is about 100g and my evaporation rate is 1 g per day. My float valve allows 1/2 gallon of top off water each time the pump turns on. An Aqualifter pump flow rate is 3.5 g per hour. Based on the foregoing I am putting 1/2 gallons of kalkwater in the system in about 9 minutes or less and doing so every 12 hours. Using the one tsp of lime per 5 g is this too much too fast? If it is my option is to tie off the supply tube so the flow is slower.

Randy Holmes-Farley · Aug 20, 2017

That is likely OK at the low concentration of 1 teaspoon lime per 5 gallons of top off water. It likely is not for full strength limewater.

Can you put that pump on a timer that limits it to 1 min each hour, while still letting the float switch also limit it Those are not expensive. I got some from Home Depot a while back for vinegar dosing and other uses.

jtl · Aug 20, 2017

Thanks, Randy. I thought about the timer and that is a great solution. Do you recall the name. I need to deal with this because at some point I am going to need to increase the limewater concentration as my sps needs for Ca increase. I should add that my kalk is going into the sump at the where the overflow and skimmer is located so pretty high flow/mixing.