Currently building a Red Sea Reefer 300 G2 but I could be building anything. I need a fitting to attach a 3/4" ID silicone hose to my return pipe on the reefer. I'm assuming it is a metric thread of some sort since it is a Red Sea setup. But how do I confirm metric or imperial and then how do I find a place to purchase the fittings? Lowes seems to have a very, very small selection. Same for Home Depot. So where can I find a good stock of various aquarium plumbing fittings, pipe and hose?