Can I use a diatom filter on another tank witbout tearing it down and recharging it?

You can use it again, but only right away and only without stopping it. What I do it put my diatom on a long extension cord and if I want to move it from tank to tank I put a quart jar in the tank with the diatom filter, then, underwater, move the exhaust and intake hoses into the jar. Now you can lift the jar out of the tank, straigh up, very slowly verycarefully of it will spit water out, suck air and turn all white in a heartbeat, but if you're carefull you can move the whole mess to another tank. If you move it from a jar to tank go VERY SLOWLY. Haste makes waste descibes this best and "waste" means all sorts of diatom power in your tank - that will come out but it looks very bad while it's in there.If you bought the recharge valve you won't have to mess with the jar. DO get one.

Can I let the filter sit unused?

Yes, within reason. A couple of days is ok, but if you let that sit for a week it'll turn into a black fetid mess. Run it every day for a few minutes and it'll be ok idefinitly

Surely I cant run something that gets this hot continuously? It's just good for an hour or two right?

Run it for 24 horus? Oh yes, with a lot of tanks sometimes mine are in operation for days at a time. They get hot, but that's ok. Think of it as free heat in winter.

It's really supposed to get this hot?

They dissipate the heat just fine. Perfectly normal. They are thermally protected so they're not dangerous.

Mine leaks!

If you assemble it right it will not leak. It may take a few tries. But, if you have a percect seal and it still leaks it may need any one of two $4 parts to make it brand new. The most important things are take care and go slowly and surely when you put it all backtogether to get a good seal. This means ZERO powder on the seal and don't let the bag get caught between the seal and the jar - it seems to happen quite a bit and sometimes you don't notice until you take apart.

Mine leaks from the hose fittings

Make sure the hoses are on the intake and exhast port TIGHTLY and have a rubber band holding them there. If it's leaking from here you should be able to see that. Just pushing the hoses on a bit harder when it suddenly develops bubble while in operation sometimes stops leaks.

How much powder for a D-1? And the Vortex carbon?

1 cup of powder. Let it coat properly per above, then add 4 teaspoons of the carbon. They're pretty sensitive to the amount of powder, too, IMO. The XL cares a bit less, but a D1 you want 1 cup no more no less. I use plastic disposable cups (great for around the fishroom) and mark them where 1 cup of power would be.Get the Vortex carbon! Makes a huge difference. There's a bit of an art to getting the power to distribute evenly, too. If the tank isn't significantly better in an hour, you havn't got the powder coated evenly.

One thing that seems to help is when you have the thing charged with new powder, shut the motor off long enough for the powder to JUST start to fall away, then turn it back on. Do this a few times and she'll be right.

To clean the bag stick the EXHAUST hose into the kitchen faucet and blask hot and cold water through there for a couple of minutes. done.

Maintenance is simply oil it twice a year. Look on the motor casing, you'll see two holes with an arrow that says "OIL". If it says "710" then you're holding it upside down. There's a (bad) picture of the oil hole location here in case yours is unreadable: image of diatom filter

Sewing machine oil works. Any light oil will, trannmission fluid is a bit better though. Synthetic transmission fluid is the best. Find somebody with a Porsche and beg 20 cc of it from them - that's a lifetime supply.