Magnets are a marvel of the modern world and they are integral to the aquarium hobby being found in a huge range of devices and accessories. Without the attractive field of magnets we wouldn’t have water pumps, return pumps, dosing pumps, and everything they power not to mention the magnet mounts for those pumps, magnetic frag racks, algae clips, or even the cooling fans found in most of our LED lights.
As awesome as magnets are they are not inherently waterproof and must be encased in some form of fully enclosed sealant like plastic or epoxy, but over a long enough timeline these are not impervious to water incursion leading to rust. With more magnetic components in our aquariums than ever before we are exposing ourselves to the potential for water to reach the corrosion prone material and the subsequent heavy metal poisoning that is dangerous to most types of aquarium invertebrates.
We have a massive toolbox of various magnetic parts that are used in many different DIY applications but we are always suspicious of their waterproofing knowing that every one of them will one day succumb to ingress of water. While inspecting the collection this week we came across more than a couple examples with serious waterproofing failure leading to swelling and rusting – some of these failed water magnets could be used outside the tank but we generally tend to dispose of them just to prevent any accidental usage in the future.
With so many brands now throwing magnets into everything from algae scrapers to magnetic frag mounts there is more danger to aquarium life than ever before that poorly encased magnets will be used in these products. Never assume that these companies are all doing their due diligence to ensure that these magnets are robustly made because for sure some of the lower quality magnets are destined to become exposed to water in the future and will poison your aquarium animals, especially corals.
There’s nothing worse than doing ‘everything right’ in an aquarium only to have all that hard work jeopardized by a poorly made magnet that poisons your fish and corals. Take a moment to inventorize all the magnets in your aquarium including your pump impellers and mounts and inspect them on a regular basis to ensure that they are as sealed as when you first installed them. Don’t be alarmed, we don’t want to give you the impression that there’s an ‘epidemic’ of failing magnets going around the hobby but it’s just good preventative maintenance to just double check and make sure your magnets are in good working order.