How does the topoff system work?

The topoff controller turns on and off a device when it senses that you tank's water level changed. There are two standard setups, A pump and reservior or a solenoid setup. In the pump setup, a pump sits in a reservoir of fresh water and replaces water that evaporated out of the tank, a little at a time, minimizing stress on your inhabitants from a change in salinity. In the solenoid setup, a solenoid connected to your water system opens as needed, filling your aquarium automatically.

For dosing chemicals, add supplements to your topoff water, and keep your reef balanced by slowly adding chemicals over time. Note: Do not run chemicals through the solenoid!

How do I hook up the system?
Determine where you would like to set your water level. Attach the switch(es) to the mount using the included cable ties at the desired water level(s). Keep in mind that the water level will be approximately in the middle of the PVC cap which surrounds the switch.

Next attach the mount to your tank or sump, putting the float switch(es) on the inside of the tank so the water can come into contact with the switches. Plug the power cord into the wall or power strip. If you don't already have your aquarium's electrical devices connected to a GFCI, now would be a great time to consider installing one.

Plug in the device(s) that you would like the topoff to control, into the cord with the female socket. The topoff controller will power the female socket depending on the level of your water. You can attach multiple devices to the controller by using a power splitter or power strip as long as the total wattage does not exceed 1800 Watts.

Note: If you have a single switch controller you can reverse the opeation of the controller by reversing the float so the float magnets are on the bottom.
What is a GFCI and why do I need one?
A GFCI (ground fault circuit interrupter) monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit. It is able to sense a mismatch as small as 4 or 5 milliamps, and it can react as quickly as one-thirtieth of a second.

This can be a very valuable device to have your electrical equipment plugged into, as aquariums have multiple electrical devices submerged in highly conductive fluid full of expensive inhabatants.

You can install one yourself and they cost as little as 10$ at any home supply store.
Is the water level adjustable?
Yes, the mount has multiple sets of holes drilled in it. You decide what level you would like your water to stay at, then mount the switch(es) accordingly using the included cable ties.
  • Tank Mount: water level is adjustable from 1" to 3" below tank lip.
  • Sump Mount: water level is adjustable from 1 " to 9" below sump lip.
How do I know if it will fit my tank?
The mounts come in three models: 1", 1.5", and Bend your own. The threaded nylon screw will secure the mount if your tank lip is within the range specified below.
  • 1" mounts fit tank lips between .25" to 1"
  • 1.5" mounts fit tank lips between 1" to 1.5"
  • Bend your own model arrives as a flat piece of plastic. You will need to bend it yourself using a propane torch or similar.
How do I bend the plastic on the "bend your own" model?
You can use a propane torch on low heat at a distance of about 8-12". Move the plastic in the heat of the torch where you want the bend to be and flip it over heating both sides. After 1-2 minutes of heating it will be soft enough to bend around a piece of wood or similar. Clamp in place and let cool.
How can I minimize the frequency of switching from my topoff?

The switch is quite sensitive, within 1/8” or so. The pvc guard will help slow the sump waves but won’t completely prevent them. There are 2 holes drilled in the top of the pvc guard that surrounds the switch. Try plugging one of the holes with putty which will slow the water flow entering in and out of the switch and prevent excess switching. Another thing to try would be to drill 1 or 2 small holes in a 1¼” pvc cap and use it to cover up the bottom of the switch or add a snail guard to your cart from here.

Do you build custom mounts?
We can build custom mounts to fit almost any application. Usually this means bending a mount to fit a different tank lip size or making a longer mount to accomodiate those deeper sumps. Most custom mounts will require $10 extra, and may delay shipment of your a few days. Please email us and ask about your configuration before ordering.
Custom Mount Building Fee: $10.00 Additional for most applications (email first)    
What is the purpose of the double switch?
There is the possibility of the switch getting dirty and sticking, pumping all your topoff water into the tank. The double switch provides an extra layer of protection by shutting off the topoff pump if the water level triggers the top switch.
How do I clean my switch and how often?
I recommend cleaning the switch monthly to remove salt creep and gunk buildup. Remove the plastic retaining clip that holds the float on and clean the parts with warm water and a q-tip or pipe cleaner. The float is reversible so take note whether the magnets inside the float are on the top or bottom so you can reassemble correctly (Magnets go up for normal operation). Don't forget to clean the 2 holes in the top of the pvc slosh guard, and the holes in the snail guard if you have one.
How big of a pump can the switch handle?
The switching system is done by a 15 Amp relay, rated to 1800 watts.
How can I prevent my topoff from starting a siphon?

If your topoff reservoir is taller than your sump you may need to make a siphon break so your topoff pump doesn't start a siphon between your reservoir and your sump which would continue until the two water levels equalize. To accomplish this, you need to allow for air to enter the tubing from your reservior to your sump.

One method is to use a piece of pvc pipe as tall as the max water level in your reservoir, then insert flexible tubing from the reservoir pump into the pvc pipe a few inches. This allows an air gap where the pvc pipe and flexible tubing meet will break the siphon.

You could also put a T fitting (or just poke a hole) in the tubing above the water level which will allow air to enter and break the siphon. Make sure your reservoir has a cover, because when you put a hole in the tubing, water will come out of it when the topoff pump turns on.

How does the solenoid work?
The solenoid is an electronic valve capable of handling the higher pressure of RO or water systems. The valve opens when powered, and remains closed when not energized. A topoff controller is normally required to use a solenoid, however some people have setup a timer to control the solenoid to open for a few minutes per day.

A solenoid is commonly placed on either the source or output of your RO system. If your RO system does not have an an autoshutoff valve you will probably need to install the solenoid on your water source to prevent your RO system from generating waste water when the solenoid is closed.

Using a solenoid connects your tank or reservoir to an endless water supply, therefore double switch topoffs are highly recommended.   Make sure to connect your water system to the high pressure input side labeled "IN" on solenoid. Connecting the solenoid backwards will cause water to slowly leak through the valve.

How much is shipping?
$10 Shipping and Handling (added automatically to your cart)
All domestic orders ship next business day by Priority Mail . This typically takes 3 days (4 for west coast, not including Sunday).

Express Mail® is our fastest service. Guaranteed next-day and second-day delivery nationwide or your money back.
    USPS Express Shipping Upgrade: $15.00 Additional    


Canada Shipping: You must add one of the following two shipping options. Failing to add the extra shipping costs will delay your order.
   Canada Shipping Upgrade (International Priority): $10.00 Additional    

   Canada Express Shipping Upgrade (International Express): $20.00 Additional    


Email for International rates and information.
How do I pay?

Paypal is our preferred method of payment. It is a fast, easy, secure service.    

Is there a warranty?

We warranty our topoff controllers and solenoids for 2 years. If you have a problem don't hesitate to email. We will not be held liable for the misuse or failure of the products.

For all other inquires, please email: sales@autotopoff.com