Dosing Kalkwasser in a 230G Reef ?

When limewater is exposed to carbon dioxide it will begin to form calcium carbonate.  This is probably what you are finding at the bottom of the container.  To reduce this somewhat be sure to mix with cold water, keep the container covered as much as you can, and don't overstir when mixing it, never shake it to stir.  It cannot be prevented completely.  Adding a few teaspoons of vinegar to the mix will also help.

I would recommend cleaning any precipitation out of the jug every time you refill it.  Never allow it to enter the tank. 

The amount and frequency of dosing limewater completely depends on how well it is maintaining your Alkalinity and to a lesser degree, how well it is maintaining the Calcium level.  If you have a lot of corals and they are lowering your Alkalinity quickly then you will want to dose limewater 24/7 every day to replace 100% of the evaporation.  If you have only a few corals you may only need to dose ove a week.  In my personal opinion I believe it's best to dose it every day either 24 hours or the 12 hours opposite the lighting period and control the Alkalinity level using the amount of lime added to the water.

What do you mean by dip it?

The raw precipitate is probably a mix of undissolved lime and Calcium carbonate crystals.  It is bad for your tank for either of those to enter your tank undissolved.

If you have confidence that the lime and the water you are using is perfectly pure then there is no harm in dissolving the precipitate in more water and dosing it.  I don't have that trust level so I advise to throw it away.

OK, that's what I thought you meant (drip), I was just making sure.

i don't know if this helps but i have a 6 gallon bucket under my tank with an automatic top off. but i just add 3 spoonfulls of kalk everytime i refill my top off bucket. once a month i take the bucket out and rinse it out. but i have it set up to where my hose is kept 3 inches from the bottom of the bucket so none of that build up gets directly in my tank. i don't know if it's right but it works for me, and my tank is sps dominant tank. but what bang guy is saying is that you need to figure out how much calcium and alk your corals are using a day and figure out how much kalk you will need to replace the calcium and alk used. you can't just go off what the bottle says because every tank is stocked differently. i do weekly water changes and dose just half what it reccomends and my corals grow fine.