I have heard of sulfur dioxide in ponds!
Is that where it would form?
I suppose the fish could disturb a pocket and get a mouth full whilst looking for food in the mulm?
I believe it's very nasty to inhale?
I generally don't run during freezing and keep air hole via heater and aerators. Not problem for 7 years or so. An equipment pad could be located behind the skimmer - there is a space under the deck in a corner but still behind a retaining wall. It would be below water level - so I would need to check head to upper biofall - it's probably 10' or so.
So thoughts on filtration? Would the bottom drains be more effective running thru a settlement tank? Or directly thru the filter?
Again trying to keep it easy but I suspect as my pond size grows and fish load grows - there will be daily maintenance.
Waste removed immediately doesn't need to be bio converted by the filtration system. Explains the popularity of RDFs and sieves effectively removing solid waste quickly. Setting chambers can be effective also if accumulated waste is removed several times a week. Often just a quick waste water dump from the bottom of a few gallons is all that is needed to remove a large portion. Going directly to a filter such as a bead filter is common but the least desired. Often plugging the filter during string algae outbreaks.
The real Batman wears polyester! Don't be fooled by the plastic imposter.
Thanks for the response. So how would you handle filtration for a layout as I have above? I’m strongly leaning away from bottom gravel -
Recommend brands and setup? I am ready to purchase soon - and realize what I thought was a simple project may not be the case
Lol
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Greetings,
I had -- until about 2 weeks ago -- a small (~ 1300 gallon) pond in my backyard. I have been a bit of tweaker / experimenter with this pond over the past few years, and I decided to try an under gravel filter last year. As far as I can determine, I built the under gravel filter consistent with the instructions advocated in the recent "Pond Trade" articles. My experiences were mixed:
The positives:
1. Prior to this under gravel filter, I had nearly always dealt with pea-soup green-water algae with this pond (full sun). Using the under gravel filter, I did find that I was able to support pretty clear water without having to use a UV. That was the biggest plus.
2. The water quality, in terms of nitrification, checked out pretty well.
3. This type of filter strategy worked well with the airlifts I was using at the time.
4. The gravel looked kind of cool.
The negatives:
1. Gravel is very heavy, and modifications to this type of filter -- once installed -- are difficult.
2. Over time, I found that I was growing a considerable amount of carpet algae -- much of it on the pond bottom. It is harder to clean a gravel bottom -- even with a Pond vac.
3. For reasons completely unrelated to the pond itself (we are planning to build an addition to the house), I had to decommission the pond (did I mention that gravel was heavy?) When I removed all of the gravel, I did not have foul odors present (as from accumulation of hydrogen sulfide), but there was quite a bit of mulm in that gravel. My suspicion is that eventually -- had I kept the pond going in that configuration for longer -- I probably would have built up some anaerobic pockets in that gravel.
My personal conclusion is that the concept indeed works, but that there are probably better ways to filter a pond. As someone who has enjoyed trying out different filtration strategies, I would consider carefully the prospect of putting a lot of gravel into a pond, as changing filtration strategies later on is not a trivial matter.
Lastly, if someone were to consider this type of filter for themselves , I would highly recommend a means by which the gravel bed could be periodically cleaned -- probably by incorporating a powerful air-blower to blow through the pipe network.
Best of luck with your project.
I've seen the UGF concept successfully implemented as a stand alone filter outside of the fish pond. More of a planted separate bog filter. These filters also had a much higher ratio of pipe volume to bottom surface area installed vs the ones in the article. They also had the ability to drain waste water from the filter bottom. The actual pond was clean bottom.
Aquascapes also has a Snorkel and Centipede bog/wetland filter setup. This allows periodic bottom clean out (sump pump) through the snorkel and helps force flow through dead zones. All of this is also available through some big box stores as rural home waste setups at a fraction of the Aquascapes cost.
If looking for a more natural filtration setup (separate tank) with plants the anoxic concept can't be beat. This concept is easier to clean and maintain long term.
Last edited by batman; 04-14-2021 at 01:07 PM.
The real Batman wears polyester! Don't be fooled by the plastic imposter.
I think there's a delineation to be made here. It appears that what you are trying to build is a very beautiful water feature with koi in it as opposed to an "ornamental" pond dedicated to viewing and growing koi. There's absolutely nothing wrong with the former so long as you don't have the expectations of the latter in terms of koi development and growth.
If you don't mind placing your koi in a temporary holding tank while you clean out the bottom of your pond/bog/stream once or twice a year then I think a grid would be fine.
Batman,
I've been thinking hard about this one. It's one of the reasons I'm working on setting up proof of concept anoxic baskets in the greenhouse pond, using kitty litter and flourite. The idea for the outdoor pond filtration at this point looks much like the color drawing you posted, in a DIY version.
The filter would be about 14" deep, and be right next to the pond itself. The surface area would be about 30% of the pond surface area. I'd do a pipe channel setup, with maybe some egg crate lighting diffuser on top of the pipes. Then I'd have a layer of anoxic baskets. These would be surrounded by, and topped with, pea gravel, so I could get good flow-around. I'd likely have bog plants planted directly into the baskets. I'd make something so I could drain the 'filter' with either a pump or shop vac. I'd have a small (2" high?) waterfall for return into the pond.
Really? That would be awesome. Do you have a link?
Thanks in advance,
Best,
Bill
Currently looking at a greenhouse build for myself with a possible separate anoxic filter. I like growing pond plants. I'll just go the conventional route with bare baskets on bottom (elevated 4 inches) and planted baskets on top. Easy to use sump pump for yearly cleanouts and baskets make plant maintenance much easier.
What ever you decide look into pre-filtration to remove most solids from the bottom drain circuits before sending to filter. Sieves and RDFs are great.
Here's some under gravel diffuser examples from Menards. These give a great open area under the gravel for adequate flow distribution. Plus can be hooked to large pipe for pumping out. 14" deep will be on shallow side for using these
Last edited by batman; 04-14-2021 at 04:24 PM.
The real Batman wears polyester! Don't be fooled by the plastic imposter.
Another option for a shallow setup would be 4" slotted tile hooked into a sump basin.
The real Batman wears polyester! Don't be fooled by the plastic imposter.