Kalkwasser quantities question  9/21/10
Hi Guys
<Hello Malcolm>
I have a question relating to how much Kalkwasser mixture I might safely inject into the system water without screwing the PH etc.
<Ok>
I'm building an auto top-up system comprising monitored float switches controlling the flow of RO water into a Kalk stirrer which then dumps into the sump return.
<I would NOT do this>
The display and sump system hold some 700 litres (~185 gallons) of water and currently looses around 9 litres (~2.5g)
<Per day? That is a lot'¦ too much to be topped up with a Kalk mixture>
with evaporation and skimming.
There's no dosing pumps involved as the RO is exiting the filter reservoir directly. The only flow rate limiting will be a JG tap on the output of the stirrer.
<I see and understand why this set up seems desirable, but it is a recipe for disaster>
My question comes down to what volume of Kalk solution could I safely add in one hit without causing problems. From a mechanical point of view, the greater the quantity the better as its easier to set up the
float switches to detect a greater drop.
<The problem here is that if you have a leak on your system, or are away for a few days and you have an abnormally high evaporation for some reason, or if the float switch fails then the top up will dose Kalk to your system continuously, flooding the system with not only Kalk, but freshwater as well. If you must set this up, then consider utilising a freshwater solenoid valve on a timer placed on the exit of the RO unit. This way you can also control the amount of water added per day. The Kalk just wants to be dripped slowly, overnight only, a few minutes per hour using the timer & solenoid, with the float valve in the sump as a fail-safe. This is still not ideal, but is much better. You might find that this is not enough to keep the system topped up, which is why the best solution overall is not to have the Kalk linked to the top-off, but to have it dripped slowly overnight from a separate reservoir.>
Do you think I could get away with one or two litres per dump?
<No I don't. For this amount of evaporation I think you need to run these separately, or run just the freshwater top-off and forget the Kalk>.
Appreciate your thoughts on this.
<You have them>
cheers
Malcom
(Australia)
<Simon>
Re: Kalkwasser quantities question  9/21/10
Thanks for the quick reply Simon.
<No problem Malcom>
Well that modifies my thinking somewhat then.
<Indeed so>
I think I can still have my cake and eat it to by 'T'ing off the RO system's reservoir and feeding the Kalk stirrer via its own timer driven valve.
<Yes, this would work. You are relying on the solenoid failing closed here, but I have never heard of one failing open so you should be ok. Another option is a peristaltic pump from an actual reservoir not the RO unit>
I'm trying to avoid a separate tank that feeds the stirrer and needs its own auto top-up.
<Ahh, understood, but this is the safest option>
Part of the attraction of what I have is that the main RO system has enough oomph from its own pressure reservoir to dump 15 liters into the sump in about 10 minutes via 1/4" tube.
<Yes, hence the danger should things go sideways>
No pumps required so less to fail and float switch triggered for about a 2 litre min/max variation to top-up.
<Understood, but I would use the float switch as a back-up and control the input of fresh water with a timed solenoid>
The evaporation rate I mentioned is not so great for Australia and as I have covers over most of my sump, its lower than most... Winters worst as the humidity is so much lower than summer.
<Running any Kalk drip separately to your main top-off is wise here>
What would you be setting the drip rate at night for then - Say one drip every 5 seconds for 10 minutes every hour 10PM to 6AM?
<Something like this, for overnight pH maintenance with some calcium addition, yes. But it really depends on what your purpose for using Kalk is. I only use it for the purpose just stated, with a calcium reactor for my main additions, but if it is your main source of calcium then the animals and your testing of calcium & pH regularly when you start will determine how much you can add. You need to measure the pH carefully am and pm for a while, and change the drip rate/ timings as appropriate. Kalk can really push pH up quite considerably if you are not careful. To repeat, the amount needed is dictated by your system, set up and it's requirements. Have you gone through these? http://www.wetwebmedia.com/kalkh2ofaqs.htm>
Regards
Malcom
<Simon>

DIY Tunze Kalk Dispenser 1/25/08 Hi, <Hello.> I bought Tunze Osmolator 3155. I am wondering if there is an easy way to DIY the Kalk dispenser 5074 that comes with Tunze. Regards, Kash <All you need is a simple plastic container that has a removable, seal able top; such as sports bottle, some tea pitchers, even a soda bottle can work. The Tunze unit has the output near the top and the input on the unit near the bottom. In theory it mixes freshwater with the Kalk as it comes in at the bottom. Tread or glue two hose barbs in their respective spots, put an anti siphon valve flowing into the unit and you will have functionally the same thing. Good luck, Scott V.>