question about diy auto top off

[UFO8MyCow]

I am trying to figure out how to set up my auto top off and since I have never had one before I have a question.

I will be using compac 10-782 pp float switches (one for on off and another for an overfill fail safe) and a 12v relay to control a 12v peristaltic pump that is rated for 60ml/min but my concern is that the switch has a gap of .035 in between when the reed switch closes and opens witch in the return pump area of my sump (5"x12") is equal to 35ml. and if I use 1/2 gallon of top off water per day (just a guess) will turn on for 35 sec 54 times per day

I am planning on using an on delay relay that would wait 10 sec before turning on the pump should i use an off delay of a minuet or two as well or should i just find another float switch that has a longer travel?

 

[Aqualund]

You should use everything the same, but then add an additional float switch and do a latch configuration. Then you will have two floats, one on top and one at a specified depth below that. What will happen is that it will take both of them to "close" to create a latching condition (and close the relay) and power the pump, but then it will take both of them to "open" in order to open the relay and stop the pump.

This keeps you from getting the bounce like you're trying to avoid, and then not having to worry about timing the relays properly.

 

[skeeter_ca]

I use a multi-event timer (up to 9 per day). It shuts off the system for as many hours as i want and have it come on at equal intervals just a little longer than it takes to replenish the sump. That way if any thing does go wrong it cannot over fill the sump. Just one more safety net.

 

[odj22sailor]

So i take it that no one trusts a float switch to turn on or off on its own? I was just going to use a float from a toilet and mount it to the side of my holding tank.

 

[geekengineer]

I bought some of these switches they take up less room I would think and not that expensive.. I think you could probably fine these on e-bay as well.

http://www.amazon.com/Pieces-ZP4510..._1?s=industrial&ie=UTF8&qid=1448833152&sr=1-1

 

[Aqualund]

So i take it that no one trusts a float switch to turn on or off on its own? I was just going to use a float from a toilet and mount it to the side of my holding tank.

No actually, they really don't.

 

[geekengineer]

No actually, they really don't.

salt creep can clog it up right? I am new to ATO saltwater myself so I don't have any experience with it.

I also bought one of these for my emergency shut off detector on the DT. I haven't set it up yet. It has the advantage of it doesn't have any moving parts, but more expensive.

http://www.ebay.com/itm/231727990883?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

 

[Aqualund]

salt creep can clog it up right?

Yeah among other things. It's just not a reliable permanent solution.

 

[zachts]

Yeah among other things. It's just not a reliable permanent solution.

It's a good backup for the backup float switch. But even if you keep it perfectly clean all it takes is one pesky baby snail or something to crawl up and prop it open and you have a major flood.

Probably fine in a QT or temporary holding tank but not a display.

 

[zachts]

for the OP, another option that would give you more travel and reliability would be using a pressure switch, gives you about an 1" of variation between on and off, and also no moving parts anywhere near the water to clog up.

Spectrapure sells them but you can DIY one for a heck of a lot less. I'm quite pleased with mine used on my DT, zero maintenance in the last 8 years or so.

I've also ran just single float switches and a small peri pump for my frag tanks (no sumps) without issues, they do need frequent maintenance though to ensure they don't bind up, but the slow pump rate on mine means it would take the better part of a day to fill the last inch of the tanks to cause a flood. I still should add a backup float switch but haven't gotten around to it yet and probably won't until I have a flood, course it's in the basement on a concrete floor so doesn't really matter. If it was in my living room that would be a different story.

 

[UFO8MyCow]

Do you have any info on the diy pressure switch?

 

[zachts]

Do you have any info on the diy pressure switch?

not off hand, never built one. I just bought mine, at the time I couldn't find the parts, though I probably didn't look hard enough. I do recall seeing a few DIY threads using it but don't have the link,

It's comprised of three main parts (plus the power supply), a sensor board that has an attachment for a hose, a relay to control the top off pump, and the tube that the hose connects to used as the "sensor" larger or longer tube gives more fluctuation in water level.... Should be able to find what you need from one of the arduino sites like spark fun or just on ebay/amazon.

fancier and more accurate setups use two sensors and a microcontroller to read ambient air pressure and keep the level more accurate.

The one I have is just a single sensor and no processor as far as I can tell, so it does fluctuate. High/low mark moves by about an 1/8" or so depending on ambient air pressure.