Question about Little Giant - 3-MDQX-SC Inline Pump

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Hi, I have an inline aquarium pump made by Little Giant (Model 3-MDQX-SC that stopped working after I turned it off. The problem came about after I turned it and I could NOT restart. The pump is currently hooked up to the sump and protein skimmer of my saltwater aquarium, so it would be difficult for me detached just to check on the motor. Please let me know if you have a solution or simply just need to replace with a new pump?

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Sounds like you need to get that pump off, take it apart and give it a good cleaning in vinegar. I have 135gal reef tank and do mine about once every 6 mos. You need to have cut off valves on each side so you can take it off when you need to. Go to They can answer any question you've got!

Posted on Jun 14, 2009


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1 Answer

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1 Answer

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