MonKei

I hate it when I forget to do stuff like that. I check, doublecheck and recheck stuff and still make mistakes. I think my biggest problem is not planting myself like a tree until something is done. I go off to do other stuff thinking I won't forget... and forget.

Welcome to RA.

Just thinking as an engineer and aspiring reefer here, but do redundant floats actually help? It seems to me that either way you program the floats, you still have a single point of failutre in one direction or the other. If the switches operate as an OR circuit (ATO turns on when either drops), you have doubled your chances of a switch sticking down, resulting in overdilution and overflow. If the switches operate as an AND circuit (ATO turns on when both drop), you have doubled your chances of a swtich sticking up, resulting in no topping off and salinity increase.

Not trying to be difficult - just trying to plan for the day when my wife finally finishes her residency and I have both the time and the money to get into reefs. Thanks!

Originally Posted by crewfish13

Just thinking as an engineer and aspiring reefer here, but do redundant floats actually help?

Not being difficult at all, something I thought of when I set it up

I've got them operate in an AND circuit, both drop it completes the loop and the pump gets power. I generally give them a quick wipe down when I do water changes, so I get rid of whatever grime/algae buildup is on them. I have, however, seen a large turbo snail stick to one of em (since I'm running sumpless right now they're tucked away in the back of the display) which actually pulled the switch down due to the weight, had i not had a second unit connected, I'd probably have had a flood =) So it's probably a personal preference and/or where you've got the floats located. If you're planning on running in the sump/return area, your likelihood of having issues like that are probably significantly lower.

I think i used Marc's DIY ATO idea that's posted on his reef page, just added the second unit for redundancy. In my new setup, I'll probably just have one switch.

And since then, I created a new top off system for my reef using two float switches that both have to be down for the water to flow into the sump from my ATO reservoir. If either one rises, water stops.

Great story about the turbo - hadn't thought about that type of scenario. After a little more thought, it definitely would make more sense as an AND. If you're taking care of your reef, you'd catch the water loss soon enough that salinity changes and losses would be minimal.If the ATO sticks on due to an snail and the tank overflows, the reef would be a complete loss (wife would make me get rid of it)!

Originally Posted by melev

And since then, I created a new top off system for my reef using two float switches that both have to be down for the water to flow into the sump from my ATO reservoir. If either one rises, water stops.

Sounds like a great idea, I may need to go find new switches...

Yeah mine is single circuit that either float will break the circuit if they rise.