Zephrant
Premium Member
Here is a quick run-down on building an auto-topoff system, that utilizes a float switch and an AC solenoid. This is designed to be used in a sump of any kind. In my case, I had an internal baffle that I could install the switch in, that did not need to be water tight. This switch can also be screwed in to a Ã"šÃ‚½Ã¢â"šÂ¬Ã‚ bulkhead directly through the wall of the sump if desired.
Tools needed:
First, go to www.mcmaster.com and order a Polypropylene solenoid- Part 7877K53, for $18.12 each.
While you are there, order an AC float switch- Part 46515K41, $15.13 each.
Hit Home Depot and pick up a pair of 1/8ââ"šÂ¬Ã‚ÂNPT to Ã"šÃ‚¼Ã¢â"šÂ¬Ã‚ Speed-Fit adapters for $1.50 each. Using Teflon tape, screw then in to the solenoid.
Acquire a two prong power cord, or some cord and a plug as needed. If you have to cut it off of a lamp in the front room, unplug the lamp firstââ"šÂ¬Ã‚¦ and mention to the wife that you think the bulb is burned out in your way back downstairs.
Ok, get out the soldering iron, and heat shrink tube, we are going to work.
Cut the wires off even, and strip 1/4ââ"šÂ¬Ã‚ off of all ends. Put a little electrical flux on each wire, and apply the iron with some solder (this is tinning the wire).
Slip a 1/2" piece of heat shrink tube over the wires as shown. Slip a larger piece over the AC cord too. Now here is the tricky part: Using a vise, or your hands, hold the two wires end-to-end, so the 1/4" tinned part overlaps. Touch it with the iron for a second, then hold them together until they cool. Done right, this takes only a second, and the joint is clean, and shiny.
Wire up as follows- The AC power cord has two wires. One goes to the float switch (white wires), the other goes to the solenoid (red wires). It does not matter which of the white or red wires attaches to the AC cord. That leaves one white wire from the float switch, and one red wire from the solenoid unattached, so attach them together. Only 3 solder joints, and already we are done. Slip the heat shrink over each joint, and heat with a heat gun. Slip the large piece of heat shrink over the other joints, and shrink it down too. This will help prevent water from getting in the joint, and give it more ââ"šÂ¬Ã…"œstrain reliefââ"šÂ¬Ã‚Â. Make sure all the wire joints are fully covered. Smear some silicon on them if you are concerned they will ever contact water.
Stand back and plug it in. Flip the float switch around, and you should be able to hear the solenoid open and close. Unplug it, pat yourself on the back for not smoking anything, and lets continue.
Now comes the fun part, drilling the tank when water is in it! Lower the water level as far as possible, but at least 3ââ"šÂ¬Ã‚ below the hole. The hole needs to be at the water level you want to keep in the sump. Keep in mind that it is not adjustable later, without re-drilling. I used a Forstner bit from Harbor Freight, but a small hole-saw would be fine too. Lay a paper towel over the water, under where you will drill, and drill away. Use a cordless drill, and keep reminding yourself that the drill is shot if you drop it in the tank! Drill slowly, and donââ"šÂ¬Ã¢"žÂ¢t press hard. When you get almost through, go even slower.
Using a 1/2" pipe thread tap, tap the hole. In my case, I was taping 3/8ââ"šÂ¬Ã‚ acrylic, and it went in pretty easy. Make sure you use the correct tap handle for the job.
Pull out the paper towel, with the drillings on it, and chuck it. Use a net to fish out any stray plastic pieces.
From the back side, screw in the float switch. It only needs to be snug, but it does need to be right-side up. In our case, we want a float-up to be ââ"šÂ¬Ã…"œoffââ"šÂ¬Ã‚Â, and a float-down to be ââ"šÂ¬Ã…"œonââ"šÂ¬Ã‚Â. Use a O-ring or two on the back side if you canââ"šÂ¬Ã¢"žÂ¢t get it snug in the right position, or if you are going for water-fastness. Use Teflon tape on the threads as well if needed.
Attach the water from the RO/DI unit to the inlet of the solenoid, and another line to the outlet. In my case, I ran the output line to the Kent mechanical float valve, which is set higher in the sump. If the solenoid ever fails open (unlikely, as it is a normally closed valve) the float switch will prevent the sump from getting too much fresh water. Mount the solenoid securely up out of the way, so it canââ"šÂ¬Ã¢"žÂ¢t ever get wet. Tie-wrap the wires out of the way.
Plug it in, turn on the RO/DI feed line, and twiddle the float by hand to make sure it comes on, and goes off as desired. Using a valve, adjust the flow to a trickle. If something fails, restricting the flow will mean you have more time to notice before you are attempting a freshwater Reef tank. Keep a close eye on it for a day or two.
Note that this is an ideal setup for a Kalk reactor too- Just put the kalk reactor after the solenoid, and donââ"šÂ¬Ã¢"žÂ¢t use the Kent float valve.
Total cost: $36 plus that stolen lamp cord.
Disclaimer: I currently believe that the above components are usable as described, and are salt-water safe. However, use at your own risk, and if you blow up anything, take pictures, but donââ"šÂ¬Ã¢"žÂ¢t go blaming me!
Zeph
Tools needed:
- Drill
- 1/2" NPT Tap
- 3/4" Forstner bit
- Soldering Iron, solder, flux, heat shrink tube
First, go to www.mcmaster.com and order a Polypropylene solenoid- Part 7877K53, for $18.12 each.
While you are there, order an AC float switch- Part 46515K41, $15.13 each.
Hit Home Depot and pick up a pair of 1/8ââ"šÂ¬Ã‚ÂNPT to Ã"šÃ‚¼Ã¢â"šÂ¬Ã‚ Speed-Fit adapters for $1.50 each. Using Teflon tape, screw then in to the solenoid.
Acquire a two prong power cord, or some cord and a plug as needed. If you have to cut it off of a lamp in the front room, unplug the lamp firstââ"šÂ¬Ã‚¦ and mention to the wife that you think the bulb is burned out in your way back downstairs.
Ok, get out the soldering iron, and heat shrink tube, we are going to work.
Cut the wires off even, and strip 1/4ââ"šÂ¬Ã‚ off of all ends. Put a little electrical flux on each wire, and apply the iron with some solder (this is tinning the wire).
Slip a 1/2" piece of heat shrink tube over the wires as shown. Slip a larger piece over the AC cord too. Now here is the tricky part: Using a vise, or your hands, hold the two wires end-to-end, so the 1/4" tinned part overlaps. Touch it with the iron for a second, then hold them together until they cool. Done right, this takes only a second, and the joint is clean, and shiny.
Wire up as follows- The AC power cord has two wires. One goes to the float switch (white wires), the other goes to the solenoid (red wires). It does not matter which of the white or red wires attaches to the AC cord. That leaves one white wire from the float switch, and one red wire from the solenoid unattached, so attach them together. Only 3 solder joints, and already we are done. Slip the heat shrink over each joint, and heat with a heat gun. Slip the large piece of heat shrink over the other joints, and shrink it down too. This will help prevent water from getting in the joint, and give it more ââ"šÂ¬Ã…"œstrain reliefââ"šÂ¬Ã‚Â. Make sure all the wire joints are fully covered. Smear some silicon on them if you are concerned they will ever contact water.
Stand back and plug it in. Flip the float switch around, and you should be able to hear the solenoid open and close. Unplug it, pat yourself on the back for not smoking anything, and lets continue.
Now comes the fun part, drilling the tank when water is in it! Lower the water level as far as possible, but at least 3ââ"šÂ¬Ã‚ below the hole. The hole needs to be at the water level you want to keep in the sump. Keep in mind that it is not adjustable later, without re-drilling. I used a Forstner bit from Harbor Freight, but a small hole-saw would be fine too. Lay a paper towel over the water, under where you will drill, and drill away. Use a cordless drill, and keep reminding yourself that the drill is shot if you drop it in the tank! Drill slowly, and donââ"šÂ¬Ã¢"žÂ¢t press hard. When you get almost through, go even slower.
Using a 1/2" pipe thread tap, tap the hole. In my case, I was taping 3/8ââ"šÂ¬Ã‚ acrylic, and it went in pretty easy. Make sure you use the correct tap handle for the job.
Pull out the paper towel, with the drillings on it, and chuck it. Use a net to fish out any stray plastic pieces.
From the back side, screw in the float switch. It only needs to be snug, but it does need to be right-side up. In our case, we want a float-up to be ââ"šÂ¬Ã…"œoffââ"šÂ¬Ã‚Â, and a float-down to be ââ"šÂ¬Ã…"œonââ"šÂ¬Ã‚Â. Use a O-ring or two on the back side if you canââ"šÂ¬Ã¢"žÂ¢t get it snug in the right position, or if you are going for water-fastness. Use Teflon tape on the threads as well if needed.
Attach the water from the RO/DI unit to the inlet of the solenoid, and another line to the outlet. In my case, I ran the output line to the Kent mechanical float valve, which is set higher in the sump. If the solenoid ever fails open (unlikely, as it is a normally closed valve) the float switch will prevent the sump from getting too much fresh water. Mount the solenoid securely up out of the way, so it canââ"šÂ¬Ã¢"žÂ¢t ever get wet. Tie-wrap the wires out of the way.
Plug it in, turn on the RO/DI feed line, and twiddle the float by hand to make sure it comes on, and goes off as desired. Using a valve, adjust the flow to a trickle. If something fails, restricting the flow will mean you have more time to notice before you are attempting a freshwater Reef tank. Keep a close eye on it for a day or two.
Note that this is an ideal setup for a Kalk reactor too- Just put the kalk reactor after the solenoid, and donââ"šÂ¬Ã¢"žÂ¢t use the Kent float valve.
Total cost: $36 plus that stolen lamp cord.
Disclaimer: I currently believe that the above components are usable as described, and are salt-water safe. However, use at your own risk, and if you blow up anything, take pictures, but donââ"šÂ¬Ã¢"žÂ¢t go blaming me!
Zeph
. I think that the moderators should change your handle to DIY Guru. Thanks for the great posts.
