Ideas For Auto Top-Off

[apex82]

I just use a timer with a slow pump (toms aqualifter)

[sphelps]

I would suggest using two electric float valves wired in series with one mounted slightly higher than the other in the sump. Run the float valves in series with a rainbird sprinkler solenoid valve and 24VAC transformer. The current draw on the valve is less than 1A so you don't need a relay. A couple bushings to reduce the 1/2" or 3/4" valve input and output to 1/4" will be needed. Run the transformer on a regular digital timer for added safety so it can only be activated to set amount of time. Whole system should run you around $80 to $100.

[untamed]

The thing with a float valve is... Should extra water flow through, this increases the water level, increasing the pressure shutting off the float. Unless the float breaks right off, they are pretty reliable.

[sphelps]

I remember talking to a guy a while back who used a kent abs float directly connected to his RO. Worked fine until his heater suction mount came loose and his heat fell against the float. Apparently it destroyed his entire tank and caused significant water damage in the house, said it was over $10K in damages alone which his insurance did cover but the tank was a total loss.

Realistically any system can fail but it's wise to add some kind of safety system to a direct water connection. A solenoid valve and a timer is fairly cheap and no doubt a good idea.

[Pescador]

It's better to put the float in a container and use a top up from that if you can.
And there is the TDS creep issue if your using DI.

Melev has a couple good articles here

http://reefkeeping.com/issues/2007-05/ml/index.php

http://www.reefaddicts.com/content.p...thy-of-concern

[fishytime]

I would suggest doing away with all mechanical float switches altogether and go with a tunze

[HL649]

After looking into this a little deeper I am now leaning towards an optical float switch and a solenoid valve. Probably build something along the lines of the optical version on Autotopoff.com. Might even get lazy and just buy one.

Anyone know a good source for optical float switches? I don't think the solenoid valve should be too hard to find.

[asylumdown]

Originally Posted by fishytime

I would suggest doing away with all mechanical float switches altogether and go with a tunze

+1

If you need the mechanical valve so your auto-top off reservoir can draw water directly from your house, you should set it up to fill a bucket/container next to your sump. Then have a Tunze system with the pump in the bucket.

The risk will be that if it fails, you'll end up with a flood on your floor, but that's a risk regardless. At least this way if the mechanical valve fails you'll still have your tank in pristine condition to console you while you're replacing your flooring.

The other option is just having an auto top off reservoir you fill manually next to your tank with the Tunze auto-top off. Less ideal because it requires work, but I fill mine maybe once every 4 days, and if I have to go out of town for longer than that, I can set up a larger rubbermaid in front of the tank and put the Tunze pump in it (just remember to also move to output end of the hose on the main tank if you do that as well!)

[globaldesigns]

Originally Posted by fishytime

I would suggest doing away with all mechanical float switches altogether and go with a tunze

+1, I too use the Tunze. It has never failed me and is probably to most reliable as it uses a IR sensor instead of a float switch for your water level monitoring. Also comes with a float switch to sense too much water if the unit itself ever goes crazy on you.

It will cost you $200 or more, but well worth it.