Best water topoff switch?

[dpdash]

I thought I had the best one but came home to a flood and a white tank yesterday. This switch had a second failsafe as well, the entire switch was clean and there was nothing wrong visibly, still haven't figured out what happened. What is the simplest and best switch available?
Thanks

Also, I bought this switch from someone on Reefcentral who makes them, can't remember who it is, anyone know this switch?

this is what I have.
http://img.photobucket.com/albums/v130/dpdash/watertopoff.jpg

[tgreene]

More than likely your skimmer went haywire and started draining your sump, at which time your top-off did exactly what it was supposed to do... It detected a low water level and switched on to fill your sump.

Since you said you had a white tank, that obviously means that your top-off is also connected to a Kalk reactor, so you've encounted a Kalk overdose in the process. This generally leaves your tank looking like Nuclear Winter just hit, and the pH spikes.

To prevent this from ever happening again, you need a Milwaukee Instruments SMS122-Reversed pH controller. With this in place, you can set the highest allowable pH limit (I use 8.6) which once that level is reached due to kalk dosing, it will shut down the top-off system until the pH subsides. If the pH remains high, the top-off simply cannot add any more water/kalk to the stystem, which also prevents a continous overflow.

This cannot and will not prevent a skimmer from freaking out from time to time (as most smaller units will), but it will prevent a saltwater tank from becoming a white freshwater tank with a pH level above YOUR setpoint.

I've not had a single incident in over 1.5 years, since installing one of these!!!

Also, since this is a very specialized item, next to nobody carries it, so you should call Bryan @ Milwaukee Instruments to find out who carries this particular controller. Be sure to tell him Tim Greene suggested this item, and for this particular use!

Milwaukee Instruments
252-443-3630

[porthios]

or you could use a dosing pump to handle top off duties..

[Reefbox]

I have been using plastic simple Kent float valves for years and I have never had a single problem with them (knock on wood).

[tgreene]

Dosing pumps require constant adjustment based upon evaporation rates, and float valves don't work well with Kalk...

[dpdash]

Thanks for the input, looks like the topoff switch did not fail as suspected and there was not a siphon from the resevoir either. Skimmer overflow is likely but don't know why.