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chrisfraser05
09-07-2011, 10:19 AM
Hi guys.

I've built my own auto top up unit for RO water on my marine tank and thought I might share for those who fancy a little project!

You really don't need alot of electrical skill to make one, just be prepared to take your time and don't be afraid to ask questions.

Heres the parts I used.


Power supply.

For this I simply went into the big box of old electrical items in my attic.
I used the 12v power supply for a netgear router. The output current is 1.5A or 1500mA. This is larger than the 1200mA the pump uses so is fine.

Caravan pump

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/submersible_pump_10l__36570_std.jpg
http://www.johnscross.co.uk/products/Submersible-Water-Pump-10-litre-flow.html

Hobby box/electrical enclosure

http://www.maplin.co.uk/general-purpose-abs-plastic-box-a-e-series-43708


Switch (inbulit light)

http://www.maplin.co.uk/slim-rocker-switches-19260?ordercode=RD17T

Relay

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/Relay.jpg
http://www.tlc-direct.co.uk/Products/SR504.html?source=froogle

wire

Float switches

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/liquid-water-level-sensor-horizontal-floating-float-switch-102630n.jpg
http://www.sourcingmap.com/liquid-water-level-sensor-horizontal-floating-float-switch-p-102630.html?currency=GBP&utm_source=google&utm_medium=froogle&utm_campaign=ukfroogle

Perspex

chrisfraser05
09-07-2011, 10:20 AM
So we'll start with the diagram.
First this is the diagram with the circuit with the power off;

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/Autotopupoff.png

Next the power is applied.

Because the water level is below the float switches the motor is running;

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/Autotopupon.png

Lastly the water level raises and closes the lower of the two switches, the motor switches off;

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/Autotopupstop.png

If the lower switch fails the water level will continue to raise until the higher switch closes instead. I've set these about 1" apart.

chrisfraser05
09-07-2011, 10:25 AM
I'm going to have to skip some steps here because I already bulit mine a while back. Basically cut the holes for the switch and wires out of the box then mount it.

Wire her all up and I've put a connector block outside the box for my float switches.

(ignore the extra switch, I've got extra bits for another circuit built into my box)
http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/DSC04398.jpg


Next I cut some perspex for my float switch holders;

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/DSC04379.jpg

Little bit of heat and bent the perspex into shape;
http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/DSC04381.jpg

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/DSC04382.jpg

chrisfraser05
09-07-2011, 10:29 AM
http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/DSC04380.jpg

Next holes drilled to mount floats. First one fitted;

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/DSC04383.jpg

both mounted (dirty sump!!!);

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/DSC04399.jpg



Lastly pump dropped into RO container...... Viola!!!!

http://i524.photobucket.com/albums/cc321/chrisfraser05/Auto%20top%20up/DSC04400.jpg


One point to not at this point. ensure the hose is ABOVE the sump waterline. If not you will get a syphon back into the ro container and cause issues.



Hope this is of some use to you guys,

Chris

genocidex
09-07-2011, 04:00 PM
i think this belongs in the diy section but it looks good, i would go with an active dry sensing circuit. came across it the other day and it looks like a 4$ build and it seems solid. as long as you use a 12v water pump
if your interested ill send u a diagram of the circuit

chrisfraser05
09-07-2011, 05:15 PM
I'd be interested to see the diagram bud, I'll not be changing this system as its working A+ and easy for my wife to understand when I'm not here (50% of the time!)

I'm always interested in seeing new ideas though ;)

korith
09-07-2011, 05:37 PM
Interesting set up. I use an ro setup as well that tops off a brute trash bin, have had the float switches get stuck on me twice now. Looks like you used 2 float switches to build in some redundancy into the circuit? Good idea.

Cliff
09-07-2011, 05:39 PM
Nice thread Chris

You've got me thinking about trying this in one of my tanks

genocidex
09-07-2011, 06:14 PM
http://i274.photobucket.com/albums/jj242/lifelessregrets/electronics/Untitled-1.jpg


thats only good if you can read schematics. basically the wierd olive green things will sense conductivity between them, if its higher than air it will activate the relay that can be open, or closed, or both if you need it. depending on what pins you tie the circuit to lol.

but your set up is ace, im not trying to put it down at all :)

chrisfraser05
09-07-2011, 06:15 PM
Interesting set up. I use an ro setup as well that tops off a brute trash bin, have had the float switches get stuck on me twice now. Looks like you used 2 float switches to build in some redundancy into the circuit? Good idea.


that was a major worry of mine so thats why I have gone with the two.

the higher one is completely out of the water in normal running where the bottom one is "floating" just above the switch on point. If algae or detrius were to build up and it were to stick when it went all the way down I would only see an extra 2lt ish of topup before the top one shut the pump off.
This would only be 1/2 % of the total tank volume so the param differance overall would be negligable.

I also though of doing a version with a third switch working reverse.
The switch would be in the RO tank and if the RO level dropped too low it would stop the pump from working.


I move my pump into my fresh salt water buckets when doing a WC.
I drain water from my display but when the return chamber level drops it adds fresh salt water. Makes it much easier!

Lastly, its an easy method of dosing bicarb. I worked out my weeks dose (6g of bicarb) and add it on a sunday night along with filling the RO tank back up.
This week I saw a drop of 0.2Dkh so will dose 7g this week into the RO and test again next week.

Cheap way to dose without a dose pump.

chrisfraser05
09-07-2011, 06:20 PM
http://i274.photobucket.com/albums/jj242/lifelessregrets/electronics/Untitled-1.jpg


thats only good if you can read schematics. basically the wierd olive green things will sense conductivity between them, if its higher than air it will activate the relay that can be open, or closed, or both if you need it. depending on what pins you tie the circuit to lol.

but your set up is ace, im not trying to put it down at all :)

I like that bud. Defo a more complex but smaller (and lets face it, more modern) approach. I'm in the middle of doing a part time college course (4 years, eekk) in electrical and electronic engineering.
My plan is to use my project phase to design a complete automation system. Your schematic may just come in handy ;)

My system will encorporate auto feeding (frozen and dry), temperature, PH, Alk, LED/flourescent lighting and flow.

Can't wait to do it, will be an easy way to sell it to the wife lmao

genocidex
09-07-2011, 06:26 PM
teehee sounds good, im looking into doing all sorts of things like that too :P

korith
09-07-2011, 06:31 PM
that was a major worry of mine so thats why I have gone with the two.



I've had my float switch fail on me twice now. Thankfully the ro unit doesn't fill up the bin that quickly, so only a few gallons ended up on the carpet/kitchen floor each time. I think I will be adding a second float to my setup, for some reason adding a second one never even occurred to me.

labnjab
09-09-2011, 11:31 AM
I'm using pretty much the same auto top off system chrisfraser05, except ours came in a DIY kit, but with pretty much the same parts. It works awesome and the only trouble I've had is when coraline started building up on the 1st float switch. One day it just didn't float anymore, lol, but luckily the 2nd switch stopped the pump. After that I made it a point to clean the switches every few months.

I use a aqua lifter pump for ours, so if the reservoir goes empty it doesn't burn up a pump, since the aqua lifter can pump air and water.