Gravel vacuum

Performance & sizing

Core numbers for matching this unit to your tank and electrical plan.

Power

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Flow rate

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Noise

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Dimensions

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Price range

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Tank fit (L)

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Consumables & maintenance

Follow the manufacturer schedule for seals, impellers, media, and other consumables.

Description

A siphon does two jobs that the Merck Veterinary Manual documents in separate chapters, and the second one catches people out. The first is the water change. Merck's description of old tank syndrome is the argument for owning one. In tanks where changes are small, infrequent, or replaced by topping up evaporation, the biofilter consumes bicarbonate as it converts ammonia, total alkalinity falls, and pH slides down. Fish adapt to a slow slide and show nothing until it turns fast, at which point it can kill them. Once a tank is in that state the correction has to be careful, because raising pH quickly turns stored ammonia toxic: small daily changes first, then regular large ones from then on. A siphon is what makes the regular large change a five-minute job rather than a chore that gets postponed. The second job is parasite control. Ichthyophthirius, the white spot ciliate, leaves the fish and encysts in the tank, and Merck notes that while encysted it is refractory to chemical treatment. What does reach it is mechanical: the cysts can be removed by thorough cleaning and removal of debris from gravel substrates. Vacuuming during an outbreak is part of the treatment, not tidying up around it. One rule comes attached to the tool. Merck lists siphons alongside nets and buckets as equipment a quarantine tank keeps exclusively for itself, disinfected and stored dry between uses. A hose carried from the quarantine tank to the display tank is the cheapest way to waste a quarantine. A note on hardware rather than on the source: tube diameter decides how deeply the gravel lifts, and a wide tube in fine sand pulls the substrate up the pipe instead of the detritus out of it.

Sources

• merckvetmanual.com — https://www.merckvetmanual.com/exotic-and-laboratory-animals/aquarium-fish/management-of-aquarium-fish
• merckvetmanual.com — https://www.merckvetmanual.com/exotic-and-laboratory-animals/aquarium-fish/parasitic-diseases-of-fish

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