Reservoirs are made for custom liquid-cooling loops in PCs: they hold the coolant, let you fill the loop and help push air out of it. Our range has over 100 models, mostly from ALPHACOOL and SINGULARITY, along with BARROW, CORSAIR and BITSPOWER.
How to choose a reservoir
Capacity and size. A larger reservoir holds more coolant, so the temperature changes more slowly and the loop is easier to fill and bleed. It still has to fit in the case, so measure the free space beside the radiator, fans or case panel first.
Mounting. Cylindrical reservoirs are usually fixed with brackets to a radiator, case panel or fan mount, while some attach directly to a distribution plate. Choose according to where your case has room and how you plan to route the tubing.
Pump compatibility. Many reservoirs connect straight to a pump, and some are sold together with one. If you already own a pump, check that the reservoir's connection and mounting suit that exact model, not just a pump from the same manufacturer.
Ports and threads. Most PC liquid-cooling parts use a G1/4 thread, but the number and position of ports vary. Make sure there are enough for inlet, outlet and filling, and check whether fittings are included, as they often have to be bought separately.
Material and looks. Reservoirs are usually made of acrylic or similar clear materials, with metal or plastic caps. A transparent wall lets you see the coolant level, which helps when filling and maintaining the loop. If your case has a side window, lighting may also matter.
Brands in our range
- ALPHACOOL: a German manufacturer known for a broad custom liquid-cooling line in which reservoirs sit alongside its own pumps, radiators and fittings.
- SINGULARITY: mostly offers design-led reservoirs and distribution plates meant for a visible, styled loop.
- BARROW: a Chinese maker known for liquid-cooling accessories and fittings at lower prices than many rivals.
- CORSAIR: a PC component maker with the Hydro X series for custom liquid cooling.
- BITSPOWER: a Taiwanese manufacturer known for fittings and acrylic parts for custom loops.
- AQUA COMPUTER: a German manufacturer known for its aquaero fan and pump controllers as well as liquid-cooling parts.
- EK WATER BLOCKS: a Slovenian company that specialises in custom liquid cooling.
Also in our range: STEALKEY CUSTOMS and PHANTEKS.
Frequently asked questions
Does a liquid-cooling loop need a reservoir?
Not every loop requires one, but most custom loops use one. It makes filling easier, shows the coolant level and helps remove air. Without a reservoir, filling the loop is more awkward, so beginners are usually better off with one.
What size of reservoir should I choose?
Choose the largest reservoir that fits comfortably in your case. More coolant volume helps keep temperatures steadier and makes filling simpler. Just leave enough room for tubing and fittings.
Where should the reservoir go in the loop?
It normally sits just before the pump so the pump is always supplied with coolant. A pump should not run dry, so the reservoir outlet should be at the lowest point. This is why many reservoirs connect directly to the pump.
Will any reservoir work with any pump?
No, compatibility depends on the connections and mounting. Reservoirs sold with a pump are already matched, while separate ones must be checked for thread and bracket fit. Compare the dimensions and connection types stated for both parts before buying.
