Float Switch - Vertical Mount

Click on image to zoom
View full size image

More Views

Float Switch - Vertical Mount

86% Recommend this to a friend (6 of 7)

SKU: 300100

reg. $10.99

Special Price: $9.34

In Stock: 93
Please wait...
Ships Free Today
4h 2m

365 Day Returns

What's This?

Preferred Reefers
Earn Up To 5% Back

Quick Overview

Recommended for water applications like level controllers, auto top systems or other aquarium uses.

  • Normally closed or normally open (see more)

  • Float magnet is encased inside the float

  • 48" leads (22 gauge wire) offer project flexibility

M8 fitting – includes a nut and sealing O-ring


Full Details

Standard Generic Float Switch is great for:


  • General water level control applications
  • Aquarium top-off applications
  • Humidification/de-humidification applications
  • Hydroponics projects
  • Water features
  • Air conditioning drain pan applications

Don’t use in heavy duty applications like sewage pumps.

Great for water. Check your fluid's specific gravity.

The wires complete a circuit when the float is down. You can reverse the operation by removing the clip, turning the float upside down and replacing the clip.

A pump rated at just 5 watts can destroy a float switch rated for 50 watts, locking it in the “on” position and pumping a lot of water where you do not want it.

The magnetic reeds enclosed in liquid level sensors are extremely reliable and long-lasting when utilized properly. Failures are nearly always a result of current overloading. Pumps, solenoids and many other devices that require control by a liquid level sensor carry "steady state" current ratings. These devices can draw ten times (or more) their steady state power ratings on start-up or shut-down. When the reeds inside our switches are exposed to this kind of "spiking voltage" they can overheat and become deformed. In some cases they may even weld together or break off, causing the switch circuit to remain closed (or open) regardless of the level of the float. Deformed reeds can also function intermittently, causing problems with troubleshooting. A 50 watt float switch can be destroyed by a pump rated at 6 watts and, unfortunately, it may take many cycles before the failure occurs.

Because they can destroy an otherwise very reliable float switch, care must be taken to completely isolate the switch from the current drawn by pumps, solenoids or other devices subject to spiking voltage. Resistors or diodes may be used, but the most common solution is to utilize a circuit board or a relay.

In the illustration, a relay acts as a switch for a pump, thereby isolating the float switch from any spikes that the pump may draw. The float switch turns the relay coil on and off. In this way, the only current handled by the float switch is that small amount required by the relay coil. Please consult with your relay supplier to assure that the relay current requirements are well within the specs of the float switch.


7 Items

  • Works well and has a nice long lead By MTWiley on 11/2/2015

    I have a single drain durso and have been concerned about the possibility of a snail clogging the drain so I bought one of these and stuck it in my overflow to stop the return pump and alert me before the DT overflows. These are awesome and come with a nice ~4 foot long black single cable coming off of them instead of a pair of ~1 foot yellow wires like most of the other float switches out there and I've been really pleased with it so far.
  • Perfect By sjdragonslayer on 9/14/2015

    used it to top off my ATO with my break out box for my apex. Easy peasy lemon squeezy!
  • Nice, but would like a longer wire By Polymorphyc on 6/17/2015

    The wire is about 3.5-4ft, I didn't measure it. I would have liked a little longer one. Work with Apex BoB.
  • Good for the money By Ron c on 3/10/2015

    Item as described. Better than other switches because it has a 4 foot cord which makes it very easy to wire up to your breakout box.
  • Switches shorted out after only 5 months. By Teddy on 9/30/2014

    They worked like a charm and had no issues with them until I noticed my Ph probe was acting funny. I have had 2 of these float switches running my ATO for the last 5 months and worked without a hitch. I then started to wonder what was going on with my PH probe as it was reading values of less then 4. After calibrating and pulling things out of my sump and trying to figure out the problem I came to the conclusion that both the float switches were shorting out in my sump. Once both float switches were pulled out of the sump my Ph probe's readings shot up to 8.1. All in all I am now back to manual top offs daily until I can find a more reliable float switch.
  • Float Switch By Brandon on 2/22/2013

    The float switch that i just purchased is awesome! I feel great now, knowing that i can leave and my tank will always be full!
  • Great little float switch By Harry on 2/25/2011

    This is a very nice float switch with nice long leads on it.
    The float itself is smooth plastic so it is easy to clean.
    Very nice price for a good float switch.


Ask a question

Product Questions

Can this switch be fully submerged? I would like to use it near the bottom of a trash can I use for my ATO so I can be notified once it needs to be refilled.
Question by: Jennifer Munoz on Jun 26, 2015 7:20:00 PM
Great Question,
This switch could be used in reverse to notify when levels are low. Switches can have a tendency to become stuck if left floating too long, so inspections must occur to ensure that the switch goes back down.
Answer by: Connor (Admin) on Jun 29, 2015 6:52:00 PM
What size is the Threaded Portion of the Switch?
Question by: Rory on Jan 19, 2016 1:33:00 PM
Great question!
The threaded portion is M8-1.25. It is metric, but your local hardware store should have a plastic nut that works.
Answer by: Connor (Admin) on Jan 27, 2016 2:47:00 PM
Would this work with a tunzee nano?
Question by: Yujiro on Jan 10, 2017 3:37:00 PM
Great question! Unfortunately, this will not replace the Tunze Nano Osomolator float switch. You may need to reach out to Tunze directly for replacement parts. :-)

Tunze – 512-833-7546 tunze@sbcglobal.net
Answer by: Randy (Admin) on Jan 10, 2017 5:42:00 PM
How does this switch mount to an aquarium tank?
Question by: Steve on Apr 5, 2014 2:43:00 AM
Hi Steve,
This is just the switch itself, generally as a replacement part or a DIY component. It has a threaded shaft and a nut to secure the float switch, generally to an L shaped bracket of some sort but it really depends on what your going to use the float switch for.
Answer by: Bulk Reef Supply on Apr 5, 2014 2:43:00 AM
Will this switch work with the apex breakout box?
Question by: CM on May 4, 2014 6:36:00 AM
It sure would!
Answer by: Bulk Reef Supply on May 4, 2014 6:36:00 AM