GCTEK

Large koi produce more waste than a standard in-pond filter can keep up with. Water stays slightly cloudy, pads clog quickly, and ammonia and nitrite can build up between cleanings.

A pressurized bead filter handles mechanical and biological filtration inside one vessel. Cleaning is done by backwashing rather than pulling apart filter pads, and the vessel sits outside the pond on a pad.

Ponds that benefit most usually have:

• koi or a heavy fish load
• feeding schedules that push waste levels up
• recurring fine debris in the water
• limited time for hands-on filter maintenance

For green water caused by single-cell algae, see our guide on green pond water. A UV unit works alongside a filter rather than replacing it.

GCTek covers standalone filter vessels, complete pre-plumbed systems, pumps, UV sterilizers, heaters, and backwash automation. Here is when each type fits.

Standard pressurized bead filters

PondKeeper, AlphaNano, BioMotion, AlphaONE, and AquaBead are filter vessels that pair with an external pond pump to provide mechanical and biological filtration.

Choose a standalone bead filter when you already have a pump in good condition and you want to handle the plumbing yourself.

Low Head (LH) bead filters

The AquaBead LH design bypasses the multiport valve during normal filtration mode, which reduces restriction and lets more flow through. Two 2-way valves direct water into the pipes when you start a backwash.

Choose an LH model when you run a low-pressure, energy-efficient pump, or when you want to move more water through the filter without stepping up to a larger pump.

X2 dual-pump filters

AlphaONE X2 and AquaBead X2 take two smaller pumps into a single vessel. Their internal pathways avoid restrictions below two inches, so two 1/4 HP or 1/3 HP pumps can feed one filter instead of running two separate tanks.

Choose an X2 when your pond is in the 20,000 to 25,000 gallon range and you want a full turnover roughly every two hours while keeping running costs down.

Complete filter systems

WattMizer PLUS PRO, WattMizer KoiKeeper, and PondKeeper Complete come as coordinated sets rather than loose vessels. WattMizer PLUS PRO covers mechanical, biological, and UV clarification in one unit, and PondKeeper Complete uses 2 inch unions at every connection for assembly.

Choose a complete system for a new build, or when you would rather have components matched for you than size a pump and filter separately.

Polishing and support equipment

PoliGlassBead is a polishing filter for fine particles, and UniClear uses high grade coconut shell carbon to remove color and fines from pond water. Alongside these, PondHaven carries WunderMax variable-speed pumps, ZapPRO and Zapp Pure UV sterilizers, ThermaKoi inline heaters, and the Liberator auto backwash system.

Start with the pond itself rather than the product names.

• Pond volume and fish load. More water and more fish mean more filtration capacity and turnover. The WattMizer KoiKeeper line starts with a model sized for ponds up to 2,500 gallons.
• Turnover goal. A common target is turning the pond over roughly every two hours. As a rough reference from GCTek, a 1/4 HP pump moves about 5,000 gallons per hour.
• Your pump's flow and pressure. A standard bead filter expects enough pressure to get through the multiport valve. An LH model is the better fit for a low-pressure pump.
• UV in the system. Green water calls for UV. The Zapp Pure handles ponds up to 39,600 gallons at flow rates up to 13,200 GPH, with 3 inch inlet and outlet and dual high-intensity lamps that each have their own switch.