I bought a Grand Cayman pre formed pond (165 gal) to go on the south side of my hen house in my back yard. I want to keep a bluegill or two in the pond so that in the winter I can just go flip them into my big ponds and start over every spring with new pond pets. **This may change if bluegill eat or disrupt plants**

Anyway, I think I want a bog filter after reading up on this forum and some other sites. I'd like to have a little bigger than what I need. From what I have seen, the bog is upfed with a PVC grid that has been square in the photos I have seen. Since you don't want dead flow areas within the bog substrate, does the bog need to be square?

Also, I plan to use a pea gravel bed to plant my bog plants in. How big of rocks should I use beneath the pea gravel, and are bricks or concrete chunks okay to use there as a base with the pea gravel on top? Will it hurt my system to have a lot more pump than what is called for on a 165 gallon pond? I would like to have some flow in the form of a water fall from my bog to my pond. How do I keep the fish from being sucked up against the screen in such a small pond with a big uptake pump?

Would also like a stream, but my pond will be in full sun. Would it be a problem to only run the stream pump and stream on a timer a few hours a day while I am home and let the stream bed go dry during the day? I figure this would cook the algae off the rocks before it forms into a goo slide.

Sorry for the lengthy post, but sometimes it is better to get differing views from people who know than to get waist deep into a project blindly.

Cheers
M

I have a pond of similar size here in NY. It gets full sun during the mornings. All I need to keep it fresh is a drop-in Pondmaster pump & filter. The filter just screens out gunk that I catch on a pre-filter made of craft store batting. That needs to be rinsed about twice a week as it clogs. (I keep 2 so I never put a chlorine bomb back into the filter.)

The pump makes a nice spray on the surface. I also run a large aquarium air pump for extra air, but that's probably only needed in the winter when I shut the filter down.

I broke down and got a UV lamp on a separate small pump to prevent spring time algae blooms, again not necessary.

A key filter ingredient is floating plants: I put water lettuce and let it grow to cover 50-75% of the water. That keeps algae away, gives the fish extra fresh food (they nibble the roots), and takes out the nitrates from the water.

My pond water always tests better then my inside aquarium because of the plants.

The UV filter is connected to the pump running the heron fountain. There are actually two ponds here, the bridge crosses dirt. The small left side pond is plants only.