Flow rate through bog

[myswtsins]

I am using a separate pump for my upflow gravel bog. What is an ideal flow rate through the bog for optimal filtering? Both mechanical through rocks and bacterial through plant roots. My main waterfall pump is rated 5100gph, actual gph at waterfall will be about 3100gph on an almost 3k gallon pond so basic turnover is covered already. Bog will be about 6x7x1, about 300 gallons of gravel and water. Thank you!

I did try to search for this answer but didn't find any info for a separate bog pump, all instances referred to making sure entire pond turn over rates were achieved.

 

[JBtheExplorer]

Everything I've read says slow flow. I'm not sure on an exact gph amount, but I definitely have mine slow. I'm sure someone with more experience will be able to give you a better answer.

 

[myswtsins]

Thanks JB. Yeah slow is about all I've found, just need to figure out what is "slow". I was thinking maybe 800-1000gph? All I have to compare to is my rio 12hf on my 58g RR sump. It flows at 630 @4ft and that doesn't seem like much for a 300g "tank".

Is there such a thing as too slow for good filtration in this kind of filter?

Love your siggy by the way!

 

[Waterbug]

There hasn't been any testing of bogs so the effects of different flow rates isn't known.

It also depends on what you want the bog to do. That's the funny thing about bogs, people just say they're great filters, but not what is filtered. For example, if you wanted the bog to be a bio filter the higher the flow rate the better. That would get more O2 in there. Most people use them as a settling chamber and slower would be better. If you push too much water into them you will see water piling up and flowing over the surface. That will also happen as they clog over time.

 

[addy1]

My pump is rated at 6800 gph, almost all the flow goes into my large bog, 25 or so by 5 or so feet. (of course you need to subtract pipe head pressures etc, so it is best guess estimate as to flow) It keeps the pond water tests in perfect shape and the algae / green water gone.

 

[dieselplower]

I have read research on how long water should be in contact with biomedia for optimal biofiltration. I don't remember the exact number but I think it was around 40 seconds.

 

[Mmathis]

I am using a separate pump for my upflow gravel bog. What is an ideal flow rate through the bog for optimal filtering? Both mechanical through rocks and bacterial through plant roots. My main waterfall pump is rated 5100gph, actual gph at waterfall will be about 3100gph on an almost 3k gallon pond so basic turnover is covered already. Bog will be about 6x7x1, about 300 gallons of gravel and water. Thank you!

I did try to search for this answer but didn't find any info for a separate bog pump, all instances referred to making sure entire pond turn over rates were achieved.

Will be following this, as I'm [sort of] at that stage of how much vs. how little.....

 

[Waterbug]

Tests are done on specific kinds of bio media. Closest type of filter that had testing were upflow gravel filters from years ago, but that wouldn't apply to bogs. No tests have been done on bogs, mainly because serious pond keepers have never considered them to be very good filters. In the hobby end of ponds most people don't test water at all, and almost never do any kind of testing of how anything performs. It's a lot easier to just say this or that works and in most Water Gardens no filter is needed so there's to go to the trouble of doing good tests on filter performance, or even considering other peoples' test data, because it doesn't matter.

 

[myswtsins]

Thanks for the replies. Guess I'll just wing it! Not my style but what's a girl to do?

 

[Waterbug]

That's the beauty of bogs, they're very simple. That's their main strength in the hobby pond world.

 

[addy1]

That's the beauty of bogs, they're very simple. That's their main strength in the hobby pond world.

and they work, at least mine does

 

[Waterbug]

Mine too. Worked great for growing plants. Love'em

 

[addy1]

yep growing plants and a nice filtering job for the pond. At least as far as the water parameter tests go, lack of green water, lack of string algae, crystal clear water and so darn simple to maintain

 

[Waterbug]

So people say. I've even heard they filter water cleaner than drinking water and have zero DOCs. Very impressive indeed.

 

[addy1]

laughing..........actually my pond water, which I have not tested for this recently, had less TDS (total dissolved solids) then our drinking water from the well.
My only indicator for DOC's is no foam or bubbles on the surface of the pond, like some post pictures of.