mechanical float vs electric float switch vs optical level switch???

[coralcruze]

setting up a water top off and I want to implement the best possible float switches ect. has anyone used an optical level switch? similar to one of these... http://www.dwyer-inst.com/Products/Product.cfm?Group_ID=16&sPageName=Ordering

I was wondering how well it worked? what is the maintenance on these devices? how long do they generally last? any brand to use over the other? thanks

[-Scott-]

Good question! Personally I'm a fan of electric but Ive never used an optical so I couldnt say.

[werdlone]

the tunze osmolator uses an optical/electronic sensor and works flawlessly. I have been running it for over 2 years now. I did replace the pump, but the sensor and backup shut off float have worked great. Looking at the price for the electronic sensors, might as well get the tunze system. To just answer your question, float valves can stick if there is salt creep or build up. the electronic is probably more reliable....

[MplsMan]

i have 2 of these wires into my top off:
http://www.google.com/products/catalog?hl=en&q=liquid+level+float+switch&cid=3290567489929661667&ei=f3spTLrlEpGENtmy8DU&sa=title&ved=0CAcQ8wIwADgA#p
i have 1 for lower level and the other higher in case of failure, never had a problem in over a year.

[das75]

For the last 5 years been using a simple mechanical humidifier float valve for my ATO and zero problems. No salt creep issues as it's continually flushed with rodi water.

Now have come across more than a few posts where peoples fancy optical/electrical/magnetic switches or the circuitry failed and only one where a mechanical float valve failed and that due a crack in the float (one I have has open bottom chambers so no worries there).

btw my valve goes for about 10 bucks at HD, no controller or pump needed. KISS

[teesquare]

Simple is better.....Mechanicals have never failed me - all the others have.....
T

[swenholz]

The best part about my mechanical, My water level has not fluctuated more than a few ounces in the 2 months I have had it set up. Prior to the top of (and what I had planned with an electronic top off) I would see a 1.5 gallon evaporation diffenerce in the sump evey 4 days. Thus, my salinity has been constant and absolutly 0 salt creep.

[Dave & Monica]

I've heard of the mechanical float switches controlling the RO/DI production fail. I think what you're looking at is great, but it's not cheap. I did a DIY from Aquahub http://www.aquahub.com/store/index.html and their instructions (http://www.aquahub.com/store/diygaquarium.html) allowed me to do a lot of customization. For example, I have two switches to control the level in the sump (first as primary, second as a backup). I also have a reverse switch in my Fresh water container - if the water level is too low, it shuts off the pump so it will never dry run. I've never had to use these failovers, but it's peace of mind that they're there.

I also used the same concept to put emergency switches in the display and overflow, so if the siphon were to break, or anything else, and the tank water level raises to the point of overflow, it cuts off the return pump. I've actually had that save my but a few times..

Good luck.

[Vegas.]

Float valve:
http://www.reefcentral.com/forums/showthread.php?t=1845917

[coralcruze]

I've heard of the mechanical float switches controlling the RO/DI production fail. I think what you're looking at is great, but it's not cheap.

Yup you got it... they do fail. in fact just about any mechanical part that has moving parts given time will fail. NOTHING is perfect but I did go ahead and spend the extra $$$ on this device:
http://www.dwyer-inst.com/PDF_files/ols_iom.pdf

I am so pleased... it looks great with no moving parts it seems like a no brainer. It even has two led lights (green and red) which indicate on or off operation. However, since my sump is my top off reservoir, I will have a mechanical float valve also as a secondary failsafe as well as a timer that will turn the water filter on only for a specified amount of time every day... i just didn't like the idea on coraline or salt getting on the mechanical float switches.

[teesquare]

Nice looking gadget there coralcruze! It is a true mark of waht a bunch of gadget geeks we are in this hobby!:spin2:

And - I think your havin the mechanical as a back up is a smart descision.

But I am curious - do you have salt or coraline build up on your float valve? I have never experienced that....Where are your floats located?

T

[coralcruze]

Nice looking gadget there coralcruze! It is a true mark of waht a bunch of gadget geeks we are in this hobby!:spin2:

And - I think your havin the mechanical as a back up is a smart descision.

But I am curious - do you have salt or coraline build up on your float valve? I have never experienced that....Where are your floats located?

T

this is my first auto top off actually in 15 years. I used to enjoy doing the top off and water changes the old fashioned way but not anymore ;) No I juts like looking at the tank and tinkering. I have read many threads here of people having issues with creep and coraline and also algae growing on their mechanical floats. I could see that hapening if you use your sump as a refugium and have a light in there ect.

The optical switch is really impressive and I will take a pic of it once its operational. However even though it has no mechanical parts that could fail does not mean it never needs mainenance. The lense does need to be clean in order to be operational. so salt creep needs to be managed.

[teesquare]

I suppose you could get some salt/coraline/algae on anything where enough light gets to it.
It continues to amaze me that the ONLY place I get any algae in my tank or sump is on the returns, or a Tunze or Vortech! Just the increased flow is all it takes.

Several of the controller on the market offer optional optical water level sensors and control. i have some form GHL Profilux - but have not hooked them up yet..... May have to give them a whirl.
Still...I have never had a mechanical one fail. And - I hate to admit it but the ones I use are the absolute cheapest ones - something like 5 bucks plus shipping - off of ebay - but because all things are subject to break or fail - I do like the redunancy to the two different types you have chosen. Makes sense.

T

[coralcruze]

I suppose you could get some salt/coraline/algae on anything where enough light gets to it.
It continues to amaze me that the ONLY place I get any algae in my tank or sump is on the returns, or a Tunze or Vortech! Just the increased flow is all it takes.

Several of the controller on the market offer optional optical water level sensors and control. i have some form GHL Profilux - but have not hooked them up yet..... May have to give them a whirl.
Still...I have never had a mechanical one fail. And - I hate to admit it but the ones I use are the absolute cheapest ones - something like 5 bucks plus shipping - off of ebay - but because all things are subject to break or fail - I do like the redunancy to the two different types you have chosen. Makes sense.

T

I've seen those off of ebay and other sites befor I purchased but since I already have a mechanicaql float valve(not a float switch) I decided the best redundancy is as differant a technology as I can find and this is it. at $50 each they are not cheap but than again if they work flawlessly each and every time with less maintenance or worry, how can you put a price tag on that?

[teesquare]

Forgive my brain fart...I was talking about float valves - not switch!:lol2:
The mechanical float valves are what I have been using. The way I have the system plimbed - I do not need any switches, I am using gravity.
BUt on other systems I have done, I have used solenoid based switches. I am looking forward to trying the optical switxh on an expansion I am planning.
T

[coralcruze]

Forgive my brain fart...I was talking about float valves - not switch!:lol2:
The mechanical float valves are what I have been using. The way I have the system plimbed - I do not need any switches, I am using gravity.
BUt on other systems I have done, I have used solenoid based switches. I am looking forward to trying the optical switxh on an expansion I am planning.
T

well, than I'll be sure to let you know all about it when its up and running...

[tromblydavid]

I use the air pressure switch that came with my spectrapure ro/di but then I have a Kent float valve hooked up to the line into the sump up higher in the sump as a backup. My point would be to use a second device at a higher level in case the first one fails. I would use a flood sensor in as the last defense against failure - I am still wanting to do this but haven't done so yet - been 10 years on my todo list along wth buying a b/u generator.

[jgrog76]

I have used both gravity float switch and electric float switch with no problems. Just look at them every week or two and make sure they are clean and you should not have any problems. Another big safety feature I build in is that my ato resivoir is small enough that it will not overflow my sump before it empties even if it is full. This has saved my butt once when I was using the gravity ato float to drip kalk. Bad idea as the kalk caused the float to stick in the open position. When I went back to ro/di in the top off only I never had a problem with it for two years.