DIY Holding Tank for Fish

Holding tanks are a crucial part of the serious fish keeper's set-up. They provide a place for new fish to be quarantined and sick fish to recuperate, and they also offer a safe place to temporarily house other stock or fry while their permanent tanks are being cleaned, moved or reorganized. A good holding tank is easy to clean and move, and should preferably be on standby at all times in case of emergencies, but can easily be made yourself at a low cost.

  1. Containers

    • The most obvious option for making your own holding tank is a spare glass or acrylic aquarium, but just about anything that holds water can be used. Some of the best choices are large plastic storage tubs; they are often much less expensive than a traditional aquarium and are also significantly lighter in weight.

      Added benefits of plastic containers include that they are easily drilled to make room for necessary equipment, and are nearly impossible to break or crack during normal use. Clear varieties will work fine, but try to find an opaque version if possible. This will serve as a better quarantine and recovery tank, as the solid walls prevent fish from being startled by other fish or passersby.

    Hardware

    • You don't need to worry about anything fancy for your holding tank, as long as all the equipment is in good, safe working order. A heater and thermometer are absolute necessities, regardless of what species of fish you keep; many medications require the tank temperature to be raised for treatment duration, and even cooler-water fish may need to be exposed to temporary heat increases to combat illnesses like Ich (Ichthyophthirius multifilis).

      A simple canister filter generally works best in the plastic-tub type of holding tank, and is important for maintaining proper water quality for prolonged stays in quarantine. A filter also reduces the necessity for more frequent water changes, which can be hard on already stressed or ill fish.

    Set-Up

    • Setting up your DIY holding tank system can be as simple as filling the tub with water and adding a filter and heater, but arguably the best way to make use of a holding tank is to prep in advance for new additions and emergencies by cycling and maintaining the tank with a very light bio-load (such as a few guppies or shrimp) in the interim between intended use. This guarantees that in the event that a fish is injured or a tank cracks, a ready supply of established water is nearby and on call. The holding tank's limited inhabitants can simply be moved into a main tank during new quarantine periods.