Good News!

[gcuss]

The pond I'm building with the bottom drain I asked you folks about....

We've decided to go a bit further down. We're hoping we can go 9 feet deep at the bottom drain, with the benching bring us to about 8 ft at the walls. Is it possible to go too deep?

Also, based on your advice, I'm going to have the 3800 gph pump on the bottom drain circuit. My settlement chamber has approx 6 min. of dwell time, but I'm curious what I should be shooting for on my bio filters. I've got two 100 gals containers that I'm using. Water is going through settlement, then through pump and up into #1, then gravity feeding into tank 2 then gravity back to pond. My pump is going to be moving about 55 GPM I figure with friction/elevation loss so I was thinking I would re-direct some of the water after the pump back to the pond and try and shoot for about 20 GPM into the filters to get 5 min of dwell time. Is it quite important?

Thanks,

Grant

[dOHd]

Grant,

We put in a retro system on a pond that is somewhat simular to what you are doing. 800 gallon settlement chamber that catches 80-90% of even the fine solids.

Then off to the pumps, through a very large bead filter, then through 3 100 gallon upflow in tandem mostly for the biological filtration. They used to have a really fine filter media on them, but we went with 3 different matalla matting, 30 sheets in all. Pond went from 6 inches of visibility and very green water to you can see the fishes shadow at 4 feet. Where he had been only useing the upflow with the old style matting, he had been haveing to spend 5 hours each weekend cleaning the system, now, outside of flushing the settlement chamber and backwashing the filter, he has yet to find any need to clean the upflows, and they are into the 3rd year.

Pond maintenance now takes 10 minutes a week at worst and the results are nice, where it used to take at least 6 hours and did not work.

As far as water quality, you could not ask for more. Each flush of the system each week takes about 400-1000 gallons.

I am of the mindset that no, you can not build it too deep. Unless you are talking greater than 15.

d

[gcuss]

dOHD,

Thanks for the reply. And the images. Looks like a lot of fish in there!

9' it is then. I'm really excited about the new pond, so I'd best get back out there!!

Great thread on the mud pond btw, I've been following. Talk about a solid lesson in "do it right!"

Grant

[dOHd]

Afternoon Grant

HE does have too many fish. Each year we cull out about 100 from 8-13 inch fish. When his Koi spawn, the plantings inside the pond are totally knocked flat and torn all to pieces. Many times there are Koi on top of the plantings, but find their way back into the pond.

THe customer did not want proper bottom drains retro installed, so he opted for the surface intakes, so he does have some large plumbing inside his pond which sucks IMO. But what I did have control over, you cant see. We hid it pretty well.

THe Medusa filter with the twin pumps are under the evergreen tree, and the settlement chamber is behind the large clump grass at the end of the pond.

d

[KoiCop]

Quote: Originally Posted by gcuss We've decided to go a bit further down. We're hoping we can go 9 feet deep at the bottom drain, with the benching bring us to about 8 ft at the walls. Is it possible to go too deep?

Grant . . .

I'm no whiz bang @ pond construction, but I've read that with aerated drains problems can occur with the pump if the bottom is over (I think) 8 feet. You can check with MCA (Michael Anderson), who's quite knowledgeable about air pumps.

And while your at it, think about how you're going to catch your koi. Too wide or too deep and it can be too much -- short of some humongous seine net.

[dOHd]

Don

The air supply to the air domes at that depth will suffer using some of the traditional methods of air delivery. But there are pumps that will deliver the air to 35 feet or more without a problem.

As far as catching the Koi in a deep pond, the same holds true for a very large pond as well. It does pose problems, especially if you intend to show the fish, or find the need to treat one.

I find that 5-7 feet is a great depth, and even 4 feet is acceptable if you do not intend to show the fish.

Best

d

[gcuss]

Hey Guys,

Thanks again for the input. The depth with the air pump I thought of. I've already ordered one that will pump no problem. However, I didn't really consider the catching of my fish.

I don't have anything close to show koi, and won't until I've got a good handle on keeping my water spot on. However, due to my lack of experience, I don't doubt that I may have to catch a fish or two for medicinal purposes.

The pond is just about dug (worth noting... an extra couple feet of depth, works out to a whole lot of extra dirt) It looks like final dimensions will be 13' X 8' X 9' deep. Despite having the aerated bottom drain, I elected to bench the bottom pretty good just the same. I'd like it to stay nice and clean and I'm probably on the edge of what a single bottom drain can accomplish in a 13' wide pond so I'm hoping the benching will make it happen. I guess I'm going to have to make up a seine of sorts that I could use to corral the fish into a smaller area. Shouldn't be too bad as I framing out the sides of the pond and then sheeting them with 3/4 plywood before I line it, so I'm thinking a PVC frame that's made the right size with a fine cotton mesh over it should do the trick.

Anyway, I'm off to bed, give this tired body a rest, should be finished digging by noon tomorrow and I'll get going on the "walls"/bottom drain install.

Thanks again!!

Grant

[dOHd]

Grant

If you have the slope to the bottom drain, it will happen. When you have larger fish in a pond, it will happen even faster, as they will keep anything loose in the water moving and stired up. Seen many high end ponds 30 feet long or more with only two bottom drains. and they do very well.

No worries.

d

[gcuss]

well, here we are 9 hours later... and still filling. I always thought I had good water pressure here. I can't believe how long it's taking to fill the pond up!! (kinda excited too, the longer it takes, the more water I managed to find a home for)

Unfortunately, didn't end up 9' deep. I almost had it beat and I found the biggest rock in the universe. I managed to expose all of it, but there was absolutely no way that sucker was coming out without a machine... which I can't get into my backyard without a crane. (not an option) The thing is 39" across, and about 30" tall. I toyed with leaving it in there, and fitting the liner around it, but decided against it as it would mess up my bottom drains ability to pull the junk out so I was lucky enough to move about 35 wheelbarrows of dirt, not once, but TWICE! Lucky me. So we ended up 6'6" deep at the drain, and the sides are at 5'10" and it's 13 X 8'6" plus a feeding shelf that's about 2' wide, 2' deep and 7'6" (the wife keeps calling it a plant ledge, when will she figure out it's a feeding shelf??). All in all, still deep enough for me to grow some monster pond mutts! (I hope)

Are the online calculators accurate for determining volume? My cheap little water meter gave up the ghost about 3 hours ago so I'll have to go the math route.

Main pond - 13 X 8.5 X 6 - 4972.5 gals
Settlement - 300 gals
Bio Filters - 200 gals
FEEDING SHELF - 225 gals (had to yell that in case she reads this)

Total - 5697.5 plus plumbing and such so around 5700 gals??
- the skimmer isn't in yet, but will be added next spring. Going to go with a savio unit. Kind of pricey, but I like how contained it is and with the water from the skimmer I'm going to fire it through two tetra pond pressurized filters (was thinking about a b.s. but that may have to wait for more money) then back to pond via a few jets placed to eliminate any dead water I may end up with.

Just want to get it close for measuring dechlor and such.

thanks again for all the good advice and such! I'm going to go check to see if we're almost filled up!

Grant

[kent wallace]

Bottom drains should go to settlement/prefiltration and then on to aerated bio then back to the pond. Bio-filtration has no dwell time/speed limit so after prefiltration the "dwell time is no longer an issue. Seperation/settlement/prefiltration/static fines filtration are the types of systems that have speed limits.
I normally run midwater and skimmer circuits to static filtration to remove the floating and neutrally bouyant fines that are created and live in the upper levels of the pond.
Normally I wouldn't use any type of pressurized filtration on new construction unless absolutely necessary because of the waste of energy and lack of oxygen usually associated with these systems along with the inability to see inside them when cleaning. In open unpressurized upflow static filtration a good rule of thumb is not to exceed approximately 630 gph/sq ft of tank area.
Dwell time is usually associated with settlement but static trapping is more a function of tank diameter and flow rate and less about depth. That's not to say a deep tank isn't a good thing. When trapping fines the larger the diameter the slower water travels up through the media so the depth isn't as critical as it is in settlement. The faster water travels through a static trapping filter the less it will trap.