Tank setup
Rimless and open-top tanks: mounting a feeder and keeping it dry
How feeders mount on a rimless or open-top tank: clamp ranges, brackets and pads, and why makers warn about humid air reaching the feeder.
Also listed as open-top tank, rimless aquarium
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Short answer
On an open top, a feeder clamps to the glass and sits in humid air. Check the clamp's stated range: Aquarium Co-Op's takes rims up to 0.9 in (24 mm) and comes with an adhesive pad. EHEIM supplies a bracket for open tanks but says the drive unit and air intake must not sit in the humid air of an open aquarium.
Key facts
- Feeder mounting
- Glass clamp or bracket; check the stated thickness range[1][2][3]Aquarium Co-Op: rims up to 0.9 in (24 mm), adhesive pad included. EHEIM: bracket for open-top tanks. Fish Mate F14: two supplied clamps for tanks without a hood.
- Food form to check
- Dry food kept dry; humidity can clog a feeder[3][4]Fish Mate says condensation can clog the F14 and suggests raising it 25-50 mm or air-feeding it. JUWEL says its EasyFeed can connect to an air pump to keep food dry.
- Aeration option
- Open surface helps gas exchange; keep bubbles away from the feeder[5][3]A 2020 study of 54-liter tanks found oxygen uptake strongly influenced by open water surface. Fish Mate says air-pump spray near the feeding point can add condensation.
- Check valve and pump position
- Pump above the water line; if it must sit lower, fit a check valve near the rim[6][7]Aquarium Co-Op says a pump below the water level needs a check valve and suggests placing the valve near the top of the tank so water stops at the rim.
- Light timer
- Smart plug or mechanical timer for the light, within its stated load rating[10][11]TP-Link rates the Kasa EP25P4 at 15 A and 1/6 HP; Intermatic rates the TN311 at 15 A resistive and 1/3 HP. Keep plugs away from splashes.
- Key electrical step
- Drip loop in every cord before it reaches the outlet[12][4]Aquarium Co-Op and JUWEL both tell owners to let the cord dip below the outlet so water drips off instead of running into the plug.
- Before time away
- Run any feeder while you are home first; Fish Mate advises 14 days of supervision for a new F14[3]The maker's recommendation, not evidence of reliability.
Watch out for
- EHEIM warns about open tanks. It says the autofeeder's drive unit and air-intake opening must not sit in the humid air of an open aquarium, the intake must not be covered, and the unit must never be immersed.
- Clamp ranges differ. Aquarium Co-Op states 0.9 in (24 mm) as its maximum rim; measure your glass before you buy any clamp-on feeder.
- Move air stones away from the feeder. Fish Mate lists air-pump spray near the feeding point as a cause of clogging.
- Splash zone. TP-Link rates the Kasa EP25P4 for non-condensing air only; on an open tank keep plugs and timers well away from the water.
What fits
Product details below are the seller's own description unless a source is shown. Pick the variant named for each item.
Battery feeder
Fish Mate F14 automatic aquarium feederChoose the F14 feeder. On Amazon, check that 'Ships from / Sold by' names Amazon.com or the brand before you buy.
Runs on one AA alkaline battery. Fish Mate's manual says to sit it over a 30 mm (1-1/4 in) hood hole or on its two supplied clamps, and to supervise a new unit for 14 days while you are home. That is the maker's advice, not reliability data.
Check price on Amazon Opens amazon.comSmart plug for the light
Kasa Smart Plug Mini 15A EP25P4 (4-pack)Choose the EP25P4 4-pack. On Amazon, check 'Ships from / Sold by' before you buy; TP-Link's own page links to an Amazon search, not a named seller.
For lights and other noncritical loads. TP-Link rates it 15 A but only 1/6 HP for motors, for non-condensing indoor air, so keep it away from splashes. TP-Link does not say whether it restores its state or runs schedules without the cloud after an outage.
Check price on Amazon Opens amazon.comMagnetic glass cleaner
Aqueon algae cleaning magnet, smallChoose the small size. On Amazon, check that 'Ships from / Sold by' names Amazon.com or the brand before you buy.
The seller's sizing is up to 20 US gallons or 1/4 in glass; check your glass thickness against it.
Check price on Amazon Opens amazon.com
See drum vs compartment fish feeders and automatic feeder not dispensing for clogging fixes.
Questions
Can I put an automatic feeder on a rimless tank?
Yes, if the clamp fits. Aquarium Co-Op's clamp takes rims up to 0.9 in (24 mm) and comes with an adhesive pad; the Fish Mate F14 uses two supplied clamps on tanks without a hood. Keep the feeder clear of splashes: EHEIM says its drive unit must not sit in the humid air of an open aquarium.[1][3][13]
Why does food clump in a feeder on an open tank?
Moisture. Fish Mate says condensation can cause clogging or failure to dispense, and that air-pump spray near the feeding point can contribute. Its suggested fixes include pellet food, moving the air stone, reducing airflow, raising the feeder 25-50 mm or connecting an air pump to its AIR port.[3]