Considering ATO

[molotov]

Originally Posted by sphelps

Manual floats are less reliable than electronic. Electronic has endless capabilities for redundancy and safety back-ups. Salt creep alone is enough to keep a manual float from closing.

I completely agree that salt creep would be enough to keep a manual float from closing. I also think salt creep could also cause a float switch to fail as well.

For redundancy using a mechanical float switch, I would position one mechanical float slightly higher than the main float. Should the main float ever fail, the higher float would cut water to the failed float. My thinking could be flawed but I've read quite a few reviews on BRS and people swear by them. I am new to this and definetly no pro so anyways those are just my thoughts.

[cwatkins]

+1 on the Tunze with the optical sensor. Hasn't failed me yet!

Well the little pump motor did burn out on me just recently, but I get lazy and forget to refill my reservoir on time, so the pump often runs dry. It's smart enough to turn the pump off after a bit, but I guess I let it happen too often. Opps!

[Smudge]

+1 for the Elos Osmocontroller. Easy to set up and keeps my level exactly where I want it.

[aqure591]

+1 on the Tunze ATO. It is one of the best pieces of equipment i have on my setup and I love it!

Originally Posted by cwatkins

+1 on the Tunze with the optical sensor. Hasn't failed me yet!

Well the little pump motor did burn out on me just recently, but I get lazy and forget to refill my reservoir on time, so the pump often runs dry. It's smart enough to turn the pump off after a bit, but I guess I let it happen too often. Opps!

[sphelps]

Originally Posted by molotov

I completely agree that salt creep would be enough to keep a manual float from closing. I also think salt creep could also cause a float switch to fail as well.

For redundancy using a mechanical float switch, I would position one mechanical float slightly higher than the main float. Should the main float ever fail, the higher float would cut water to the failed float. My thinking could be flawed but I've read quite a few reviews on BRS and people swear by them. I am new to this and definetly no pro so anyways those are just my thoughts.

Yes but with electronic you have options.
1. You can connect multiple floats in series by simply wiring them in series and placing one slightly higher than the next. They are also small enough to fit pretty much as many as you feel comfortable.
2. You can use a timer to control how long the ATO is allowed to activate for each day and how often.
3. You can connect multiple pumps or solenoid valves as well.
4. You can even wire in some kind of alarm to alert of whatever kind of failure.

With manual you don't have any of those options. You'll have to explain how to connect two manual floats together in series. I've never seen a manual float that can be connected that way. While you may view the manual float as one part and simple that doesn't mean reliable. One part means one part to fail, with electronic many parts have to fail at the same time for an error to occur and how many parts is up to you.

[mike31154]

I prefer the simpler approach. There comes a point where redundancy, particularly with regard to electronics becomes overly complex & self defeating. What if there's a power failure?

If I could do a gravity feed thru mechanical float valve I would. Alas, I don't have a sump & no way to elevate a top up container above my display, which is what I need to top up. So for the time being I'm using a bit of both, mechanical & electric. A 7 gallon glass wine carboy pressurized by a small air pump on a timer feeding water thru a mechanical float valve. Takes a bit to figure out the timings in order to keep the glass container pressurized enough to match evap rate, but once done it's all good.

Only failure I've had with this set up is the timer (electrical component) messing up & top up not keeping up with evap. Happened last week while I was away but since my daughter was checking in on the system almost daily, she was able to get 'er fixed up again. I often add alk, mag & calcium to the carboy in reasonable doses & the mechanical valve (designed for whole house furnace humidifier) has never failed in over 4 years now. Salt creep has never been an issue either.

[sphelps]

Originally Posted by mike31154

What if there's a power failure?

You tell me.... As far as I know electronic devices using a power system that's down wouldn't power up... So I guess the top off won't work during a power failure. Is that an issue? Timers have memory so that wouldn't be an issue. I don't know I give up...

[mike31154]

Originally Posted by sphelps

You tell me.... As far as I know electronic devices using a power system that's down wouldn't power up... So I guess the top off won't work during a power failure. Is that an issue? Timers have memory so that wouldn't be an issue. I don't know I give up...

I guess it depends on how you set up your system. Just saying that with a strictly mechanical valve, a power failure is a total non issue, since that would also stop topping off. No doubt any power failure is going to cause more serious issues with lighting, heating, cooling etc. There are of course also battery backups & generators etc. Just relating my own experience with simpler set up, less to potentially go wrong. Not everyone is an electronics wiz & knows how to properly set up a complex, rendundant system with solenoids, switches & all, not to mention cost.

[sphelps]

Originally Posted by mike31154

I guess it depends on how you set up your system. Just saying that with a strictly mechanical valve, a power failure is a total non issue, since that would also stop topping off. No doubt any power failure is going to cause more serious issues with lighting, heating, cooling etc. There are of course also battery backups & generators etc. Just relating my own experience with simpler set up, less to potentially go wrong. Not everyone is an electronics wiz & knows how to properly set up a complex, rendundant system with solenoids, switches & all, not to mention cost.

Well to be perfectly honest I'd like to see a system that would cause problems with a power failure and then I'd like to meet the person who made it.

There's nothing complicated about such a system.

1. Install 1A rated (most common) float switch at desired location in sump.
2. Install 24VAC solenoid valve
3. Connect negative from 24VAC power supply to solenoid negative
4. Connect positive from 24VAC power supply to one wire from float
5. Connect other wire from float to solenoid positive.
6. Plug power supply into a digital timer set to turn on at desired time each day for just long enough to top tank off.

That's it, if you want more security, the following two options are easy additions but not needed, system is perfectly safe without.
1. Additional solenoid, connect another solenoid directly to the other one (positive to positive, neg to neg). Plumb in series not parallel with the other one.
2. Additional float, install another float slightly higher than the first. Wire in series with the other one (power source to float 1 wire 1, float wire 2 to float wire 1, float 2 wire 2 to solenoid(s).

As for cost:
float: $5
Solenoid: $25
Power supply: $10
Timer: $20
Wire: $5
Plumbing parts for solenoid (if needed): $15
Tubing from RO to tank: $10

Total (on generous side): $90
With extra solenoid and float: $120

Not bad for an actual auto top off that doesn't require any space.

[mike31154]

Ok man, you got me, now I give up. My apologies to the OP.