Need Advice on Top off System Please!

[dandyfop]

So, the set up


Tank ||
----- || Bathroom sink
Sump ||


^
|
Wall


I know, I know, Diagram of the Month quality...


I NEED a top off system due to my sump design (and just because

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| | | | |

^ ^
Pump Baffles

I made the compartment for the pump really small in case the overflow failed/plugged. Unfortunately, it also means that any small amount of evap. seriously lowers the water level in that compartment, and makes the pump run dry.


So, I need a top off, and I need to get into some kalkwasser as I'm moving from softies into LPS.

My options are:

1) Drill a hole through the wall and run a water line from the bathroom sink into my sump area. Use it to fill a bucket with kalk and then either
a) put the bucket on top of the sump and use a simple float valve.
b) put the bucket next to the sump and use a electronic device, ATO or this one from spectrapure that uses air pressure to judge levels, and then use a pump.
c) keep the bucket under the sink and run a tube into the sump, using the above method


Acckk.. too many options, I need your wisdom!

Thanks


P.S I need to do much research into kalk. I don't need a mixer right? Just mix it in, keep the pump above the sludge, and refill every week or so?