Looks interesting. ...
Minecraft is so much more than a game these days.
Using it to show the contractor precisely how I want the pond laid out.
Early days yet so this is still an pretty raw revision. Waterfall basin is in, but not the waterfall itself.
You can see the sheer 6m high reinforced 1m thick concrete wall I have to work with.
Dilly, dilly!
So it begins.
Got back from work to find this on the doorstep of the plot.
Pile boring gear already deposited on site.
Awesome
How did they cut the house on the left like a cake?
This is what we call locally a semi-detached unit, which comprises a pair of properties separated by a common reinforced structural wall. This allows either side to be independently rebuilt.
Looks kinda like a cake sliced eh I thought the same since the dark hydraulic concrete they used to finish the wall looks like icing.
Last edited by DragonFireSG; 02-14-2019 at 12:41 PM.
It is great to have it started.
Piling work is going to take the better part of a month. I'll get more pictures when the boring is complete, and the heavy equipment is moved away.
A lot of the time actually goes to letting the disturbed earth settle in a bit.
After that, the plot will be dug up to have the foundation poured. Trenching work for the pond bottom drains will be done at this time, as the drains are set up to run under the main pour.
I'm setting up for the main pond in front empty into a lower pond running along the side of the house before the water hits the RDF chamber. The minecraft model is coming along, and I will post an update soonish.
This is the layout as passed on to the builder for the foundation pour, and structural wall rebar tie positioning.
Lower left there is a raised deck covering a freshwater storage area that will be used for topping up the pond and emergency water change.
To the lower right is the waterfall feature. The waterfall itself will be a stainless steel frame bolted onto the raised and reinforced area in dark brown. Orange is a poured concrete base that collects waterfall output before letting it flow over a wier into the pond. The lighter part overhangs the main pond, and provides a hiding area for the fish.
The area bordered by red is a above water level planter that hides the filter deck running alongside the far right fenceline from view.
The pond is divided into two. The larger section in front, and a narrower section towards the rear. All output from the front empties into the narrow section before hitting the filter, making the narrow section fairly fast flowing. I figure that with massive turnover, there shouldn't actually be issues with emptying the bottom drains into this section.
I intend for the front to be the "retirement" pool for the older, larger fish, and the narrow fast flowing section to be for younger fish where the linear flow should prove beneficial for development.
A custom ordered wedgewire sieve bend separates waste from the water before the RDFs. The sieves will be sized at 800-1200 micron so that they can handle high flow, and are intended to remove coarse debris.
The RDFs will be two asymmetrically sized units, one twice the size of the other. While they share common electronics and most mechanical parts, cost pressure means that I can only install one large unit. The common parts will ensure that there are no single points of failure. Together they can handle about 53,000 gph.
Output from the RDFs gravity flow down a channel where anoxic biomedia baskets will be laid on a FRP/GRP grate. The area under the grate is flushed into the RDF pre-chamber using a small submersible pump on a timer to prevent mulm buildup. At the end of the channel is the pump chamber where water is pumped up to the falls, and also to a zakki shower hidden behind the falls, completing the circuit. The channel doubles as a buffer zone for when pumps are stopped to reduce water loss.
Unlike most RDF installations for consumer ponds, this implementation uses high water in the dirty chamber rather than low water in the clean chamber to trigger flushing. A separate low water trigger in the clean chamber is used as a failsafe. Why I do this is because of the size of the clean chamber. Varying water levels in the clean chamber will mean a big change in the water level of the relatively small dirty chamber (dark grey). The level detectors need at least 1" delta to operate reliably. A 1" change in the clean chamber may well be a 4" change in the dirty chamber. (4x surface area in clean chamber)
This means that on flushing, I have 4" of clean screen that isn't doing any filtering when water levels normalize.
Thus, detecting a dirty screen on the dirty side maintains RDF efficiency as on flushing, I only have 1" of clean screen not doing any filtering.
The other effect of doing this is that after the system is running, I can top off the pond with a lot more water. This water would otherwise be lost down the dirty chamber overflow every time the RDF screen gets dirty. More water in the channel = lower dynamic head = lower running costs.
Last edited by DragonFireSG; 04-03-2019 at 03:33 AM.
A question I have for your consideration is... do you think I am running too light on bottom drains and returns?
I am hoping that bottom contouring and high flow rate - potentially 40,000 gph will keep the bottom relatively well swept.
My main concern is the pocket on the left. There is a big gravity return flooding the bottom with filtered water from the corner, but I am not sure if it will be enough. That area will be relatively steeply sloped from 3ft down to 4ft towards the big drain at the center. Those two pipes set into the center drain are 6" btw. That bottom drain's gonna flow quite a bit.
I'm wondering if I should cast in a couple more 3" returns at the pond corners to keep water moving towards the bottom drains. It's kinda crucial for me to come to a decision soon as any extra returns need to be set into the formwork before the foundation is poured.
Are there any skimmers? Is the air being piped over to that left side at the pond bottom?
If so I'd think it should provide some pull on the bottom and send debris up and towards
the middle. I have one pond that depends on currents and the fish to keep debris moving
and in my climate in the winter (cold) when the fish are less active, I notice more debris on the
pond floor... but as soon as temps warm a bit and they start having more interest in eating, it's
reduced to almost nothing. My guess would be that since yours is designed to be home to larger koi
with a lot of flow and in your warm climate where they remain active, it should be fine as is.
Thanks for you input Steve. Indeed the design does count to some extent on the koi constantly foraging to keep the bottom clear. I will be keeping some plecos too in the narrow section to assist with excess food cleanup. They also will probably coexist ok with younger, more nimble koi.
There aren't any skimmers per se, since the design counts on the bottom drains being inadequate to handle the total flow. The excess water will overflow a channel cut between the front and the rear, thus fulfilling the role a skimmer would usually play.
The same is true of the rear pond towards the filter chamber, where the pair of 4" pipes will not be able to handle the bulk of the flow.
It could be said that if the flow through is too slow, there will be no skimming since the bottom drains will be able to flow all the water pumped without any flow going over the channel cut-out. I am counting on that to not be the norm though.
There is air piped to the pocket on the left. The 3/4" lines fanning out from bottom left are the air lines.
I don't intend to run any air lines into the narrow section as it is physically small and there should not be any stagnant spots.
Fresh photos. Bore piles are done and capped.
The sewer inspection chamber is being rebuilt (covered spot on the top right)
Still a way to go before the foundation pour can be done.
Imagine the amount of earth that will have to be moved for that..
Most of the earth is currently piled up in front where the pond is supposed to be.
The bunch of rebar sticking out up close is part of the beam that will support the driveway.
Plenty of shade for the pond
Last edited by DragonFireSG; 04-22-2019 at 03:47 AM.
Nice to see your progress. Keep posting.
Moar progress.
Marking out the deepest part of the filter pit.
The foundation pour will go over what has been laid out so far. The pieces of timber outlining sections are being used to guide the rebar tying.
Usually the pond goes in after the house.
In this case, the pond has to go in first, since it is integral to the structure and design of the house
This pond will be massive!!!
Revision, after it was determined that some ground beams would get in the way.
Also some slice drawings I did for the engineer.
The full size rotated image is here if you would like a closer look.
https://i.imgur.com/WxKAYfy.png
The RDF channel inlet had to be modified as a ground beam meant the curved overhang could not be done.
Also, scrapped the upper/lower pond in favor of just one big uniform one. Less troubles balancing the water levels.