"Just Me "Koi"" wrote in message
...
You can install a backflow device in the system, that way water goes in to
the filter but not back out of the inlet pipe.

May I strongly suggest that you dump the water from your bottom drain into
a
bio/mechanical filter first, then from that into your veggie filter. This
way the biofilter gets all the muck and stuff first before going into your
veggie filter. If you don't, and you get leaves into your veggie filter,
when they decompose, they will generate ammonia and nitrates that will
affect your pond, and you will also need to mechanically clean your veggie
filter more often.

My plan is to build a settlement tank that will precede the veggie filter.
My thought is 3 5-6 gallon buckets from cheapo depot. The bottom drain would
feed into the first bucket. A pipe then goes from the top (less sediment
area) of the first bucket to the bottom of the second bucket. The second
bucket is piped from top to the bottom of the third bucket. The third bucket
contains a pump that takes from the top of the bucket and dumps into the
veggie filter.

I figure this will be cheap and easy to build. It should also be easy to
clean with the proper valves in place. It will also be easy to employ, as I
just need to dig a hole and drop it in. I could probably build something
similar with one large vessel using a liner, but I am thinking the multiple
vessels will help drop more sediment out. This way, I can also use it has a
mechanical/bio filter if I decide to do so.

BV.