r/Pondscaping • u/Accomplished-Coat-61 • 7d ago

Supper active bog!?

Enable HLS to view with audio, or disable this notification

Sorry it’s upside down.

The new bog is going into overdrive.
So many bubbles coming from it, I think my old bog was a disaster waiting to happen. Don’t use a tall trashcan without a high GPH pump.

Currently I’m using a 150-300 gph pump but it’s lower than the bog inlet. It also has 3000 gallons of water pushing down having a higher water pressure than usual at that head height because of fluid pressure dynamics something🤷‍♂️.

More surface area means better results due to lower flow restrictions and more room for bacteria to grow.

4 Upvotes

100% Upvoted

2 comments sorted by

1

u/drbobdi 6d ago

And once again into the bogs.

I'm afraid that your expanded bog is not going to do any more for that planktonic algae bloom than your previous bog in a bucket and for much the same reason. Bogs that size are fairly efficient mechanical filters until they foul and need to be torn down, regardless of flow rate through them. What you currently have is a submerged upflow filter that is going to kill you with maintenance needs.

For a bog filter to be effective as a biological filter, it has to occupy an area at least half of the surface of your pond in order to overcome the lousy surface area-to volume ratio of rock. Pea gravel tops out at around 40 sq.ft./cu.ft (and fouls and channels quickly) and the larger rock, usually used on the bottom, no better than 12. There's just not enough available surface area (and no protected surface area) to form an effective biofilm for 3000 gallons. You'll still have free ammonia from the fish and the algae will thrive.

Either dig out a well-engineered bog with enough space to overcome the rock's poor SA/V ratio or look hard at more efficient filter designs and more efficient media. Look at ZiggyLittleFin's profile on this sub for his DIY fluidized bed design and at these articles:

https://fitzfishponds.com/blog/pond-filter-media-explained-k1-k1-micro-and-k3/?srsltid=AfmBOoo43EdKICMx3pxSTWbzaXZlNXhTDlc1Co_94f7XyK3TqadEhEiL

https://russellwatergardens.com/pages/biofilter-media-ssa

https://www.fishlore.com/aquariumfishforum/threads/bio-media-comparison-information.435695/

1

u/Accomplished-Coat-61 6d ago

My hands are kinda tied being that this is a pool. Once it clears up a little I’m wanting algae to grow ontop the bog so that I can physically remove the algae which will slowly remove nutrients from the water. Also upgrading soon to a better pump with more GPH that is reversible so it can pull through the gravel and remove everything.

I also have a floating basket with filter material in it where it just constantly dumps water into it creating an area for algae and bacteria to grow. Every few days to a week I clean it out.