Well, well, well!!!! After reading this about the ATO, i now understand why my top up problem was happening!!!
(could not find MAD)
My significant other, Shane, has taken a job out of town and left me in charge of our 210g reef and 4 other smaller saltie tanks. I know enough to hopefully keep all up and running. The first day he is gone the sump fills level right to the very rim, almost overflowing. I think maybe a fish has jumped into the overflow and plugged the water flow. i dunno. Another member comes over to have a look, he thinks maybe the ato, but i say Oh no that is programmed by the Profilux. He suggests that i manually fill the water as needed. Anyway water slowly goes down, i keep an eye on things, talk with Shane, he says it has run flawlessly for 1yr and wonders maybe the water level in the ato bucket was higher then he normally has and that is what is causing this. I continue to keep an eye on the level that he has marked, just above the senor, ato seems to be doing its job and if not i add manually. Then yesterday am i take a look everything is fine, i come down to go outside and water is flowing out all over the floor!!!!! The brute bucket is completely empty. I pull the plugs connecting the ato and start cleanup. Even empting most out of sump. Salt level is down a bit,will raise that, but fish and corals ok. Luckly i was home. He will not be too happy knowing that it was the Profilux malfuctioning that was the problem.
I can not believe that Profilux was aware of this and did nothing, they should be found liable for the destruction in your (any) tank. These units are not cheap, price wise anyway, and people put their trust in the name.
So sorry to see the devastion in your tank that was caused by this product.