As far as restarting any external goes it is much easier if you have a means of keeping the outflow pipe from the tank (the in to the filter) full of water. Providing you can maintain the siphon starting any external filter is a doddle.

With the eheim pro filters the bit that attaches to the filter has 2 taps on it makes sure the out put pipe from the pump (the in to the tank) is drained first then release the water from the tank outlet (the in to the filter). This should maintain the siphon.

I have never had a problkem with this with eheims but no end of trouble with fluvals invariably I get the thing filled up with water then I turn it on and nothing happens because the impellor has jammed. To fix a fluval impellor jam normally hitting the top of it with a fist (basically thump it) in a downward motion seems to kick the impellors into gear.

Fluvals make a racket normally when they start too eheims are virtually silent and in my experience start first time every time. Just my experience and opinion though I know some people think they are fantastic value for money and they are right up until the point they go wrong.

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Alan

Thweeerp!