2 Types of DIY Bog filters - 12 inches of pea gravel or 3 foot of large medium small rocks?

[GaryMoz]

I'm a bit late to the party so, it would be great to hear how the bog filters are doing?

I'm just about to start my pond around 5000 gallons. I was do a aka aquascape type design however I wondering about the need of the "Snorkel" , I know the idea you can drop a pump down it to do a back flush, but if I use 4" or 6" perforated pipe could add clean out ports at the end? okay they would have to have upturn and a reduce, but then I would only have to attached an external pump?

Any holes in my logic?


ALso I was intending to use a bottom drain and a skimmer, each would be pumped into two separate sections of the filter. The reason for the bottom filter I was not intending to put rocks or gravel in the main pond section

 

[Mmathis]

Hello and welcome @GaryMoz!

 

[poconojoe]

I'm a bit late to the party so, it would be great to hear how the bog filters are doing?

I'm just about to start my pond around 5000 gallons. I was do a aka aquascape type design however I wondering about the need of the "Snorkel" , I know the idea you can drop a pump down it to do a back flush, but if I use 4" or 6" perforated pipe could add clean out ports at the end? okay they would have to have upturn and a reduce, but then I would only have to attached an external pump?

Any holes in my logic?


ALso I was intending to use a bottom drain and a skimmer, each would be pumped into two separate sections of the filter. The reason for the bottom filter I was not intending to put rocks or gravel in the main pond section

Just for clarification:

When you drop a pump down into the snorkel, you're not back flushing. You're sucking out any possible accumulated muck or dirty water.

If you build the simple version of a bog without snorkel and centipede, the clean-out stacks at the ends of the perforated pipes are used as a forward flush. You open the clean-outs and your existing pond pump pushes out any debris that may have collected in the perforated pipes.

 

[GaryMoz]

Just for clarification:

When you drop a pump down into the snorkel, you're not back flushing. You're sucking out any possible accumulated muck or dirty water.

If you build the simple version of a bog without snorkel and centipede, the clean-out stacks at the ends of the perforated pipes are used as a forward flush. You open the clean-outs and your existing pond pump pushes out any debris that may have collected in the perforated pipes.

Thanks for your reply.

If I understand it right the direction of water flow is the same in both case? Normally the water would enter the centipede at one end, the opposite side to snorkel, then be dispersed through the crates and then up through the gravel.

When you drop the pump down, the flow of water through the centipede will be the same, but the pump will also pull water down from crates and gravel?

This does make me think a valve is needed to stop water being pulled from the pond/pump?

If I don't use snorkel can I not do the same thing by shutting of the main pond valve and just sucking out?

Am I missing something obvious, it won't be the first time

 

[poconojoe]

Thanks for your reply.

If I understand it right the direction of water flow is the same in both case? Normally the water would enter the centipede at one end, the opposite side to snorkel, then be dispersed through the crates and then up through the gravel.

When you drop the pump down, the flow of water through the centipede will be the same, but the pump will also pull water down from crates and gravel?

This does make me think a valve is needed to stop water being pulled from the pond/pump?

If I don't use snorkel can I not do the same thing by shutting of the main pond valve and just sucking out?

Am I missing something obvious, it won't be the first time

I don't have the centipede/snorkel setup. I have the simple manifolds covered directly with gravel, no voids.

Hopefully others will chime in but I would think if you had the snorkel that you would shut off your bog pump, drop another pump down into the snorkel and suck out whatever might have accumulated down there. Then pull that temporary pump back out and turn your bog pump back on.

For mine, I shut my bog pump off, open the clean-out stack, turn the pump back on. I watch as black water shoots out for a few seconds. Then shut the pump off, put the cap back on the clean-out and turn the pump back on.

I believe the snorkel/centipede setup is used for larger ponds/bogs.
My bog is 14 feet X 5 feet and 12 inches of gravel covering two 10 foot long 2 inch pvc pipes with slits cut in them and it works great for my way overstocked 1800 + gallon pond.

 

[addy1]

My bog large 2 .5 feet deep only pvc pipes and gravel no clean out. Running 11 years now never cleaned except yank excess plant growth.

 

[Lisak1]

I would never recommend someone build a bog with no clean out, HOWEVER like @addy1 after 11 years of running ours we’ve never had a need for clean out. I would recommend not overthinking that element. Pump water free from debris knot the bog and there won’t really be anything to clean out.

 

[addy1]

I do draw water from a foot off the bottom.

 

[GaryMoz]

I would never recommend someone build a bog with no clean out, HOWEVER like @addy1 after 11 years of running ours we’ve never had a need for clean out. I would recommend not overthinking that element. Pump water free from debris knot the bog and there won’t really be anything to clean out.

Every day my wife tells me not to overthink, I just can't help it

"Pump water free from debris knot the bog and there won’t really be anything to clean out."
I'm intended two sections toy the bog filter one fed from a skimmer which will have s course filter and a second section fed from a bottom drain, so this indicates I should use a course filter inline with pump from the bottom drain? I had though of using a simple settlement tank before pumping to bog filter.

 

[poconojoe]

Every day my wife tells me not to overthink, I just can't help it

"Pump water free from debris knot the bog and there won’t really be anything to clean out."
I'm intended two sections toy the bog filter one fed from a skimmer which will have s course filter and a second section fed from a bottom drain, so this indicates I should use a course filter inline with pump from the bottom drain? I had though of using a simple settlement tank before pumping to bog filter.

I wouldn't pump from the bottom to the bog. You might be pulling debris into the bog. If you insist on having a bottom drain, then you will need to add some type of filter or prefilter if you want to send that water to the bog.
To me that would defeat one of the great features of a bog. The fact that a bog is almost maintenance free.
By adding a filter or prefilter you will constantly be removing it to rinse it off which will get old and tedious real quick. Too much work for me.

You could always use another type of filter and send that water elsewhere, like over a waterfall. But then you're back to cleaning a filter every so often. Again, more work.
A pond with less work is much more enjoyable. Constant cleaning of filters is no fun. It becomes a chore.

I don't have a bottom drain. I have my bog pump suspended with a thin rope to keep it off the bottom. I use a pool net to get any debris that may settle down there. I scoop very slowly. I do that in the Fall and in the Spring. I have a lot of trees too. A net goes over the pond in the Fall. I use PVC pipe as a frame for the net.

 

[GaryMoz]

I wouldn't pump from the bottom to the bog. You might be pulling debris into the bog. If you insist on having a bottom drain, then you will need to add some type of filter or prefilter if you want to send that water to the bog.
To me that would defeat one of the great features of a bog. The fact that a bog is almost maintenance free.
By adding a filter or prefilter you will constantly be removing it to rinse it off which will get old and tedious real quick. Too much work for me.

You could always use another type of filter and send that water elsewhere, like over a waterfall. But then you're back to cleaning a filter every so often. Again, more work.
A pond with less work is much more enjoyable. Constant cleaning of filters is no fun. It becomes a chore.

I don't have a bottom drain. I have my bog pump suspended with a thin rope to keep it off the bottom. I use a pool net to get any debris that may settle down there. I scoop very slowly. I do that in the Fall and in the Spring. I have a lot of trees too. A net goes over the pond in the Fall. I use PVC pipe as a frame for the net.

I agree it has to as little maintenance as possible. I hear skimmers are very good and only need minimal maintenance.

I have seen someone use a settlement tank between the bottom drain and the bog, he says he only needs to vac out tank once a year.

I guess I am overthinking a bit, as it will be quite a large pond, with the bog filter around 7000-8000 gallons, and with the the shape the build cost will be quite high, so I just want to give the best chance to work well with resorting to conventional biological pond filters.

 

[poconojoe]

I agree it has to as little maintenance as possible. I hear skimmers are very good and only need minimal maintenance.

I have seen someone use a settlement tank between the bottom drain and the bog, he says he only needs to vac out tank once a year.

I guess I am overthinking a bit, as it will be quite a large pond, with the bog filter around 7000-8000 gallons, and with the the shape the build cost will be quite high, so I just want to give the best chance to work well with resorting to conventional biological pond filters.

I had a skimmer a while back and I had to constantly clean it's filter pads and basket. Plus, small debris kept getting past the sponges and jamming the pump's impeller. Granted, it wasn't the most expensive skimmer.

There were other problems too. Occasionally a fish would get trapped inside the skimmer and floating plants would as well.
I installed a string just under the water surface to stop the floating plants from getting sucked into the skimmer, but there was no fix to keep the fish out.
I got rid of the skimmer and I net out any occasional leaves and cover the pond with a net during the Fall.

 

[GBBUDD]

I do have a PAIRon the same pipe of bottom drains and I'd not do without them on a larger pond..
I do have a standard basket strainer just like a pool pump has it catches leaves and larger stuff string algae in the beginning.. I can tell when it's time to empy it as the water flow will lesson over the falls. But to empty it you shut the pump off 1/4 turn on the lid opens the strainer I have a compound bucket . I tip the strainer over the bucket . Maybe re.ove a stuck leafe . Throw it back in 1/4 turn the cover flip the switch on. It took as long to type this out on my phone as it does to do it . If your going deeper than 3 feet and wider than 12 I recommend a main drain

 

[GaryMoz]

I do have a PAIRon the same pipe of bottom drains and I'd not do without them on a larger pond..
I do have a standard basket strainer just like a pool pump has it catches leaves and larger stuff string algae in the beginning.. I can tell when it's time to empy it as the water flow will lesson over the falls. But to empty it you shut the pump off 1/4 turn on the lid opens the strainer I have a compound bucket . I tip the strainer over the bucket . Maybe re.ove a stuck leafe . Throw it back in 1/4 turn the cover flip the switch on. It took as long to type this out on my phone as it does to do it . If your going deeper than 3 feet and wider than 12 I recommend a main drain

That's the type of skimmer I was thinking off.

At the moment I pumping skimmer into one side of bog and bottom drain into the other side, the bottom drain will go via a settlement tank. (well it does in the design).

Now I need to start building it

 

[GBBUDD]

how big of a bog ? and how many gph ARE you planning on pushing through the bog .

I hear skimmers are very good and only need minimal maintenance.

Skimmers / negative edge are critically important they removed solids before they have a chance to settle into the pond. the wider the skimmer with the shallower the intake the better.

The main drain or drains if your pond is deeper as code may require. is for the ones that got away and the fish waste as skimmers do little there