timer for auto topoff?

[Abynum1]

Someone has probably already thought of this, but here my idea:
Let your tank go for 12 hours during the day without topping it off then turn on your auto top off and time it to see how long it takes it to top off.
Do this again 12 hours later, say 8am and 8pm.
Then put your auto top off on a digital timer for 8am and 8pm for the length of times it took to top of the system at each particular time of day.
Add a few seconds if you want just to allow for extra evaporation.
This would be an added safety feature in case the auto topoff gets stuck.
Even if its stuck it would only run (roughly) the amount of time it takes to top it off.
Of course if it doesn't need the full time allowed on the timer the top off will shut it off anyway.
Unless of course they both malfunction
Is this a good idea? It seems like you get a whole new level of protection for just the cost of a timer.

[shag26272]

bad idea, your tank needs different amounts depending on temperature of the room and humidity, it wont be the same from day to day

[Abynum1]

That's why I stated to set the timer to run a little longer than it takes; to account for the variations.
The top off is going to put in however much it needs, the timer is just there for a safety precaution in case the topoff ever gets stuck.

[jdm01]

for $50-75 I got a Tsunami vaccuum operated auto top off switch. no moving parts to break and very reliable. a timer of any sort introduces a level of concern for me. What if the power fails? What if it runs too long? what if it does not run long enough?

Not trying to be difficult. I would just hate for you to come home to a real problem because the timer malfunctioned.

[Abynum1]

Again, the top off (whichever one I decide to get) is going to be working as normal.) IT will be the one that is controlling the topping off NOT the timer. The timer is just there to only allow it to come on a few times a day.
When the timer comes on the topoff does its thing.
That way,in the event the topoff ever gets stuck, the timer is only going to allow it to run for x amount of time.If the timer gets stuck on ,it doesn't matter because the topoff is going to shut it off when it gets to the desired level anyway.
If the power goes off to the timer,well it goes off for topoff pump as well ,so either way its not topping off.
Heres the two worst case scenarios:
The topoff fails: The timer shuts down anyway after a few seconds longer than it normally takes to topoff,no big deal.
The timer fails: Then the topoff doesn't get power and the sump is a gallon or so low at the end of the day.
When I get home I add the water manually like 100s of people do everyday and I replace/fix the problem with the timer.

Worst case scenario with a topoff thats NOT on a timer:
You come home to a freshwater tank.
I hope that clears things up.
They seemed to understand it and thought it was a good idea in the "Lighting, Filtration & Other Equipment" forum.

[Shagsbeard]

If your "timer" gets stuck off, your pump dries out and starts a fire.

There are plenty of fool proof top off techniques. Mine is completely gravity driven. It consists of a glass bottle (5 gal, but really want 10) a couple rubber stoppers, some rigid air tube, a length of 1" pvc and some tube. Whole thing cost me less than $10. I got the bottle for free on freecycle.

It's pretty easy to set up. You drill two holes in the stopper for the bottle and push two piece of tubing through. One reaches just the other side of the cork, and the other is long enough to reach the bottom of the bottle. Drill one hole in the other stopper, put a small length of tube through it, and stop up the end of the PVC with it. Connect the PVC tube to the short tube on the bottle with hose, and put a length of hose off the tube which reaches to the bottom of the bottle. Fill the bottle, and place the open end of the PVC just below the water line in your return area. Start a siphon into your tank from the other hose.

As water is siphoned out of the bottle, a vaccuum is formed which stops the water from flowwing into your sump. The only way this vaccuum can be released is when air enters the PVC (once the water level is below the openning).

I've been running this for a couple months now without a hitch.

[shag26272]

I just used the JBJ ATO by itself and it never gave me any problems whatsoever, I understand what you are wanting to do though

[Abynum1]

Originally posted by Shagsbeard
If your "timer" gets stuck off, your pump dries out and starts a fire.

Its a digital timer so its not going to get stuck on or off, power going off would be the problem.
When I stop the flow to the sump and let the pump run, it takes about 4 gallons before the pump is exposed, so not likely to run dry in a days time.
However If I'm gone for a few days it very well could.
However if a normal topoff gets stuck in the off position the pump could run dry as well.
I wonder what the people do who don't have auto topoffs and go away for a few days?
I like your idea,letting gravity do the work.
If this doesn't work,I may give it a try.
Thanks for the idea.

[kau_cinta_ku]

ok so if your ato is gravity fed then what does the pump and timer come into place? i am completly lost now. either way my top off consists of 2 float swithes 1 for backup. a 10 gal. storage and a small pump and love it.

[Abynum1]

kau_cinta_ku,
Your setup is the exact one I am going to do.
I'm just going to have it hooked up to a timer so it only gets power about 4 different times within a 24 hour period.