Kalk ?

[jfl14609]

In the new 210 I plan on doing kalk I just got one of the kent marine aquadose systems that holds 5 gallons of ro di. My questions is how much kalk powder do you recommend I add to the water? also what is a average drip rate to start at say one drip ever 5 seconds or so? Thanks

 

[Henry Colf]

recommended dosage is 1-2 tsp. per gallon of water. I would start with 1 and then work up to 2. So for starters 5 tsp.

 

[Dave VG]

I just started dosing it myself. Been a week so far I'm using 2 tsp per gal.

 

[mr.maroonsalty]

You can use trial and error on the drip or you can try determine the volume of each drip using something like a calibrated test kit beaker or a syringe with the stopper out and your finger over the tip. I use medical drip line that drips .1ml, there are ~3785 mls per gal, and 86400 sec per day. I evaporate ~1 gal per day, therefore, I use a drip rate a little longer than twoonethousand; when I leave the tank for a few days I sometimes nail it, but when I don't its never far off.

2tsp per gallon is fully saturated water. You should be dosing to meet the needs of the tank. When Lime dosing the first thing I watch is ph; I can't dose fully saturated lime in my tank during the summer, because with open windows my ph can run over 8.6. Next, Alk is the number to watch; a weekly test should tell you if its steadily increasing.

 

[cardiffgiant]

I always use 8 tsp/ 5 gal. It seems to give me the best saturation without having a stirrer. I also use 20ml vinegar / 5 gal which also helps a but with saturation.

 

[NirvanaFan]

You can only dissolve a certain amount in water. I think it's about 2 tsp per gallon. You may not need to do this much though.

 

[Henry Colf]

you can super saturate using vinegar.

 

[Gravesj1s]

Two things you'd want to know and it would be fairly easy to math out.

(1) How much does your tank evaporate in 24 hrs
(2) Do you know how much alk drops in 24 hrs

 

[gmneil]

i put about 2 spoon fulls per gallon in my 10g top off container i let it mix for like 2-3 hrs with an old power head then when the water clears i just plug my auto top off back in, this lasts a little over a week in my set up

 

[tmz]

When dosing calcium hydroxide,there are limits on how much the water can hold and limits on how much you can dose in a given period of time without spiking ph.Calcium hydroxide adds both calcium and carbonate alkalinity so if you are using other dosing methods you may need to cut them back a bit to insure against bumping them too high.

2 tsps per gallon is all the mixing water will hold unless you spike it with vinegar and then you can get it up to 2.72 tsps per gallon with 48 ml of vinegar per gallon of ro. Acetic acid( vinegar) is ,however, an organic carbon source which can easily fuel an oxygen depleting bacterial bloom in the tank. So if you're thinking about vinegar I'd limit it to about 12ml per gallon of ro water which will enable a meager 9% increase in the amount of kalk you can dissolve from 2tsp per gallon to about 2.2 tsps per gallon.

For starters I'd use 1 tsp per gallon and move up from there or down depending on alkalinity tests.

You have to do some math and measuring to figure the drip rate.

The max you should dose in any given hour per 50 gallons of water volume should be an amount of lime water holding no more than 1/4 tsp of kalk powder. For example, for your 200g(rounded) , you could dose 1 gallon of limewater per hour mixed at 1tsp per gallon or 1/2 gallon pr hour mixed at 2tsps per gallon.Dosing faster than this runs a rish of spiking ph and precipitation.
You can dose less per hour and a 24/7 drip is best in most situations.

A measuring cup , a clock or timer and math can help you figure the drip rate you want.

 

[redrider911]

The problem I always had was the drip rate was never consistent. The more water that was in the top off container had a faster drip rate do to the pressure of the water. As the water went down, the drip slowed, or even stopped. Has anyone else had this problem?

 

[tmz]

Well, it usually works out to around 4 to 5 hours to cover top off at a safe rate. you could calculate it for say 7 or more hours to make up for drip rate variations and use it only at night . Longer is even better in terms of conastncy of alkalinity and salinity. I used a bucket with airline hose and an airline valve and dripped it for a couple of years without a problem. Now I use a large still reservoir( 32 gallon brute can) and a peristaltic pump set for a set number of liters to be spread evenly over 24 hours.

 

[redrider911]

I think the peristaltic pump is definitely the way to go.

 

[NirvanaFan]

Tom, how come the vinegar lets you dissolve more kalk? What in it lets more CaOH dissolve?

 

[tmz]

Tom, how come the vinegar lets you dissolve more kalk? What in it lets more CaOH dissolve?

White vinegar is 95% water and 5% acetic acid.The formula for acetic acid is CH3COOH, also written CH3-Co2-H. As the acetic acid is converted to acetate by microbial activity ,CO2 is released. The extra CO2 neutralizes more O from the hydroxide . It takes 2 units of CO2 plus 1oxide to form 1 bicabonate molecule( HO3) and 1 CO2 unit and one oxide to form CO3. So adding vinegar is really adding CO2 plus a source of organic carbon and acetate . You could get a similar effect with other organic carbon sources but vinegar is probably the most efficient and easiest to use.

 

[mr.maroonsalty]

What do you think of old skool method of having several pounds of lime in a still reservoir; I'm thinking of the one pictured in Borneman's book?

 

[tmz]

I don't think it matters how much undissolved kalk powder you have in the reservoir if you want full saturation. Any extra beyond 2tsps per gallon will just sit on the bottom undissolved and mix in as more water is added with occasional stirring or as some small amount depletes via precipitation due to contact with the air.

BTW it will not loose any significant amount of strength in a loosely covered container unstirred for at least a couple of weeks based on tests done by Randy H Farley.

So if you want absolutley full strength /full saturation , extra kalk powder at the bottom of the still reservoir should do it. But the difference will be minor in a covered garbage can or similar covered but unsealed container. If you want less than full saturation, then you can't have extra kalk powder in there as it will dissolve until it's gone or a full saturation level is reached.

 

[mr.maroonsalty]

Just to be a wee bit more specific; what do think of this Tom: A 15 gallon tall with a simple glass plate for cover, a standard ro float valve in supplying rodi, ~ 1/2 f3 lime casually manually stirred once or twice per week and refreshed with new when levels fall to roughly half level, and a dosing pump calibrated to evaporation?

 

[tmz]

I don't know if the infrequent stirring would get enough calcium hydroxide to dissolve to maintain it's strength given the continuous flow of new water into the reservoir.

Further, if the contanier is not airtight , the ato water movement could introduce CO2 into the mix precipitating some CaCO3.

Typically a still reservoir is refilled with water and kalk at the same time ;stirred and then left still and covered . A thin film of precipitant forms at the surface and helps seal the solution under it.Dosing is usually via peristaltic or diaphram pump at a preset amount evenly distributed over a period of time usually 24 hours.

What you've described if sealed is more like a Neilsen type kalk reactor typically used in an ato set up with a magnetic stirrer moving the powder periodically to saturate newly added water. The seal is important because the surface agitation as teh ato water flows in will fold in CO2.
Some undissolved calcium hydroxide at the bottom may dissolve when the solution falls below full saturation but may not be enough to keep up with the new ato water without more frequent stirring.

 

[Gravesj1s]

Maroon salty,
I was using a nilsen reactor and the problems tmc described are pretty much to the "T" in my experience with it.I think its a pain in the......

benefit a large tank or one with alot of water volume.Smaller tanks I think its more of a pain than its worth.

Mines going up for sale soon.If its something you think youd be interested in PM me ,I would work a deal with you.