Introduction and first volley of questions.

[Lisak1]

The concern I expressed was not concern about bog-filtered water but rather the danger of electrocution.

Ohhhhh! Missed that ENTIRELY! I've never even considered getting myself electrocuted... something to think about!

I've never heard of a "riffle" - had to google that one! Aeration is not only important for your fish, it will also help with keeping water healthy. The bacteria that colonize the pond need oxygen, too. Waterfalls may indeed be ubiquitous, but there's a reason why they are so commonplace in garden ponds.

Can you describe your bog in a bit more detail? When you say "permeable barrier" what do you mean? And where is the sand? Is the bog depth 6 inches total?

 

[ki5ka]

Ohhhhh! Missed that ENTIRELY! I've never even considered getting myself electrocuted... something to think about!

I've never heard of a "riffle" - had to google that one! Aeration is not only important for your fish, it will also help with keeping water healthy. The bacteria that colonize the pond need oxygen, too. Waterfalls may indeed be ubiquitous, but there's a reason why they are so commonplace in garden ponds.

Can you describe your bog in a bit more detail? When you say "permeable barrier" what do you mean? And where is the sand? Is the bog depth 6 inches total?

Electrocution is not something I had considered either! Then, when I realized the submersibles are not "rated" for human or fish safety I did a bit of research and found credible government reports of people dying by electrocution from their pumps. Not something that seems to be discussed much.

Perhaps my use of "riffles" comes from my trout fishing background. That's where the fish are; trout need LOTS of oxygen. Any moving water acquires additional oxygen atoms on it's exposed surface. My 100 inches of bog outflow is roughly equivalent to 50" of laminar-flow waterfall, but laminar-flow (smooth) has exponentially less surface area than turbulent flow. The riffles in my setup are small and quiet but turbulent, apparently, between the two, I am getting adequate oxygen to the fish in their present configuration (small) As they grow, that will perhaps change, again, the reason I am considering changing out the pump I just bought!

 

[Lisak1]

credible government reports of people dying by electrocution from their pumps. Not something that seems to be discussed much.

I'd be interested in reading those - I'll have to do some research!

 

[ki5ka]

...Can you describe your bog in a bit more detail? When you say "permeable barrier" what do you mean? And where is the sand? Is the bog depth 6 inches total?

I think that it is shallower than typical. It may be deeper than 6 inches in the deepest areas, but not much more than that. I have a layer of sand on the bottom, covered by pea-gravel. Not sure I remember where I got that idea from, I've read lots of different opinions! The permeable barrier is underlayment that is held in place with the larger rocks, then covered with sand and gravel. That is now planted with watercress, which I hope will eventually overgrow the perimeter and cover the ugly, exposed shoulder of the bog.

 

[MitchM]

Make sure whatever pump you have is connected to a properly installed GFCI.
Clear water is not healthy water when you are keeping an ecosystem, your algae will give you some clues. If you can post some pictures of any algae concerns, that would be useful.

 

[Lisak1]

Your bog design is unusual. In all my reading about bogs I've never heard of anyone using either sand or underlayment in the construction. I will tell you our experience with using underlayment in a down flow bog. We built our rain exchange with several layers of underlayment between layers of gravel as we were told it would help with filtration and also keep the gravel from falling into the rain exchange. The latter is indeed true; the former is completely false. The underlayment very quickly clogged with fine sediment and prevented water from flowing through. We were cutting the underlayment out from under the gravel within the first few months of our pond being built. By year two we had to remove all the gravel and cut out all the underlayment. I don't recommend it. If you have water entering your bog that is filtered and free of all sediment you might be fine, but otherwise that underlayment is going to cause issues.

I would have the same concern with sand. People have experimented with using sand filled pool filters on ponds and find that they clog very quickly. Again, if your water is entering the bog completely free of all organic material, including fine sediment, you may not experience issues. I'm guessing the underlayment was suggested because of the use of sand. To me, the two either alone or together spell maintenance issues in the future. Just thinking out loud here - obviously I don't have any experience with this type of bog. I wonder if this was a design someone came up with for a swim pond, to mimic a sand filter in a pool?

 

[Lisak1]

Make sure whatever pump you have is connected to a properly installed GFCI.

I did do some reading on this concern last night, and found this recommendation repeatedly. Would a GFCI prevent the possibility of electrocution? I've heard of fish being affected by low levels of electricity being released into a pond, but hopefully a charge strong enough to kill a human would be preventable with the proper wiring.

 

[sissy]

welcome and anything can give you a shock no matter what it is and that is why it is better to have the breaker shut it's self off .I have all my electric monitored by the electric company online and if any thing is using more electric than it should then they send me a warning that it may need serviced or may be faulty .It was worth the time to enter everything online .I was surprised when my small electric company offered it

 

[ki5ka]

Make sure whatever pump you have is connected to a properly installed GFCI.
Clear water is not healthy water when you are keeping an ecosystem, your algae will give you some clues. If you can post some pictures of any algae concerns, that would be useful.

Hi Mitch,

Yes, the circuit to the pond is GFCI protected.

You might be on the right track, maybe our standard of clarity needs adjusting. What we find least appealing is the brown that is forming along the outflow of the bog. There is a shoulder of about 6' that shows bare liner. I'm wondering if a significant increase in flow over the edge of the bog where it flows into the pond might keep it cooler and therefore, keep it green. I have planted watercress along that edge and despite my expectation, it is rooting and surviving in zone 10 conditions If the watercress fills in and hangs down over the edge and covers it, that would be a beautiful thing. I am considering making mesh bags to anchor and hang from the rocks at the edge to root the watercress in, but it would be simpler if the stuff just grows out and naturally hangs down. We'll give that a bit and see if that happens.

 

[ki5ka]

I did do some reading on this concern last night, and found this recommendation repeatedly. Would a GFCI prevent the possibility of electrocution? I've heard of fish being affected by low levels of electricity being released into a pond, but hopefully a charge strong enough to kill a human would be preventable with the proper wiring.

In the reading I did I discovered that while a GFCI significantly reduces the risks of an "energized" pond, it doesn't eliminate it.

Those that know me are surprised at my concern as I routinely do things that involve risks but my grandkids will be in this pool, perhaps that is why I'm adamant about this one. Or perhaps it is the number of children involved in the reports of fatalities. I can't point back to any one source to cite, but I was repeatedly left with the conclusion that if there is an electric source in the water, there is a risk of electrocution. There were often, perhaps always, flaws and errors found in the wiring. The sources I referenced were government wiring codes, CDC reports, industry regulatory agencies, and such.

 

[MitchM]

I did do some reading on this concern last night, and found this recommendation repeatedly. Would a GFCI prevent the possibility of electrocution? I've heard of fish being affected by low levels of electricity being released into a pond, but hopefully a charge strong enough to kill a human would be preventable with the proper wiring.

Yes, GFCI's monitor the electrical circuit for a very small imbalance going to and coming from the electrical appliance that's plugged into it. It will cut the supply of electricity once that limit is reached.

 

[ki5ka]

Yes, GFCI's monitor the electrical circuit for a very small imbalance going to and coming from the electrical appliance that's plugged into it. It will cut the supply of electricity once that limit is reached.

Indeed, that is how a GFCI is supposed to work, but here is an article written by the senior electrical inspector for the city of St. Paul, Minnesota who explains how one may be electrocuted even with a properly wired GFCI circuit.
https://iaeimagazine.org/magazine/2010/05/16/gfcis-and-electrocution/

 

[mrsclem]

We have our ponds wired with GFIs and still lost almost every fish early on with a voltage leak from a pump. Guessing there wasn't enough to trip the GFI.

 

[Mmathis]

While I don't have a means to directly measure oxygen concentration, I am watching fish behavior for the commonly mentioned signs that indicate low oxygen concentration; fish moving toward the riffles or gulping air at the surface. I have seen neither of these behaviors so I don't think concern with lack of oxygen is warranted. Do you think otherwise?

They make kits that measure O2. If you can’t find one near you, they can be ordered online. In fact, when I got mine out just now for this pic — realized it expired 2 months ago . IMHO, it’s never a good idea to wait for symptoms to show up, to know that you have a problem — not when it’s something you can stay on top of 24/7. Moving water is important for gas exchange, and anything that causes a break in the water’s surface — like bubbles from an air stone, or the action from a waterfall or fountain — is best as gasses are exchanged at the surface. Personally, and it’s probably overkill, but I have 3 airstones, 2 spitters, the return from a small bog, and the return from a Skippy filter. My pond is roughly 3000 gallons and all I have are about 30 goldfish.

Pond O2 test kit

 

[MitchM]

Indeed, that is how a GFCI is supposed to work, but here is an article written by the senior electrical inspector for the city of St. Paul, Minnesota who explains how one may be electrocuted even with a properly wired GFCI circuit.
https://iaeimagazine.org/magazine/2010/05/16/gfcis-and-electrocution/

Right, no imbalance, no tripping of the GFCI.
If you think of an old incandescent light bulb, the pond water is the element in that case. The electrical activity flowing through the water will mess with the fish in the pond, so you could wind up with sick fish, dead in extreme cases.
A stainless steel or titanium ground probe will provide an easier path for the electricity to flow through.

One thing I wanted to mention with you using the pond as a soaking pool, is that keep in mind when you enter the pond you will be introducing organic matter from your body, phosphate from any bathing suits you are wearing plus oils and chemicals from any sunscreen. You should improve your filtration and not rely on the bogs and plants for that.