Still thinking things through, would appreciate advice

[Craig Brown]

All,

Please have a look at the plans for my Koi pond. I am new to this and after the most physically demanding two weeks of my life, I don’t want to make any dumb mistakes.


Background:

My yard has a slope. In order to create a level surface I dug about 3.5 feet in the back (near the fence). My house was built at a time when contractors sold the good top soil and replaced it with rocks and boulders. It’s surrounded by old oak trees (3” roots). Gluing it all together is a substance that is like clay which my son (a geology student) insists is actually some type of sand common to New England. It’s like hitting an endless rock. I tried using a tiller but it didn’t scratch the surface. No room for a backhoe (or money, either) so it was all done with hand tools.


Frame:

The frame was built using 4 x 6 x 10’ PT lumber. Thick 6” nails bind each timber to the timber below it. Rebar runs through the top to the bottom timber and into the ground. The walls are 2’ tall. The hole slopes down below the walls to a maximum depth of about 2.75 ‘. Using a pond calculator, I think it will hold about 1500 gallons.


I bought enough sand to cover the bottom with 1”. I bought under-layer to put on top of the sand. I bought a 15 x 15’ liner to put on top of that. Someone suggested that it might be too small and I may have to upgrade to a bigger liner. Store said it was OK.


Since I started from scratch, putting in a BD is not much effort at this point. I like the idea of a gravity BD. Please see my diagram.


I am going to make the tanks from the same 4x6 PT lumber (I had extra). I will line the tanks. If this is a bad idea, I could put Rubber made (or similar) pre-made containers in the structures (which are 3x3’) but lining them is the cheapest way to go. I don’t know what type of filtering material to put in the settling tank, as I have not gotten that far yet.


Is a Skimmer required? I plan to build a roof-like structure to reduce the fallout from the oak trees. The roof will have corrugated plastic windows to allow sunlight through. We’ve recently had a hawk move into the neighborhood and I think he may be getting tired of eating squirrel. I’m thinking the roof might help with that situation as well.

The filtering system will be covered by a deck (with removable panels for quick access to the tanks).


Questions:

Did I forget anything? Could you think of a better way to do some part of this (please … no more digging

How about the pipe size, is 3” OK?

Any recommendations for specific products (such as the BD, the pump etc) would be greatly appreciated.


Thanks in advance!


Craig

 

[Mmathis]

Honestly, Craig, not to steer you away from our forum, but with all the equipment questions [etc.] and dealing with a true koi pond, you mignt want to check out the forums at KOIPHEN. Those guys deal with these questions all the time. Most of us are just lowly gargen pond folks -- not saying we can't help, but it never hurts to get advice from other sources, as well.

 

[addy1]

Welcome to our group!

There are a lot of garden ponders on this site, but also some that have great koi ponds. You will get help but at a slower rate than in a formal koi forum.

I like your layout. Can't really help with the filters, my pond is filtered with a plant/peagravel bog

The skimmer, for me, was important, I get flowers, leaves, maple seeds falling, the skimmer does a great job cleaning the surface of the water.

A liner would work great, no need for containers for your filters.

 

[Meyer Jordan]

Am I correct in assuming that the entire filtration system will be gravity fed?

 

[Craig Brown]

I guess since I may ask overly technical question I should explain myself. I’m sort of a professional hacker. I’m one of the few original guys (yup, it was all male then) from the early 80’s that are still in the business. I describe my job as follows: “I think s**t up”. Now a days it’s usually in regard to something a bad-guy is trying to do. I’m what you call a “white hat”. If there is one thing that we security-types hate, it is to make a mistake and need to retrofit in a solution (anybody have their identity stolen lately?). I don’t plan to devote a ton of time to working on my pond. I’d like to minimize the required maintenance and enjoy it.

I am not comfortable posting in the professional Koi forums. I would rather hear what other “tinkerers” are doing. I could afford to just buy a filter, but what fun would that be? In fact, I am going to put a faux stone finish on the tank, and am learning how to make faux stones from cement (which I have never used in my life).

Anyway, I appreciate the replies. You are a friendly bunch of folks and after I get home from my day job, “friendly” is greatly appreciated

 

[Mmathis]

Thanks for the reply, Craig.

I like the idea of a skimmer, and this would be the time to make plan to install one. Though not impossible, retro-skimmers [as with BD's] are a headache to install.

Don't forget to factor in aeration. And are you still thinking about adding shelves for plants? How many fish are you planning to have? And what will you do for winterizing the pond?

 

[Craig Brown]

To answer a few questions:

Total gravity fed: I guess it is. The pump pulls water out of tank two. Bodies of water (at the same elevation) want to be at the same level so water flows into tank two from tank one. The water in tank one now “wants” to be level with the pond so it sucks water from the pond.

If any more evidence is needed to prove I am 100% geek, consider the following. The diagram I posted was simplified. In between tank two and the waterfall is a hydroponic system for growing small plants (like basil). A gravity-based system will remove big chunks of waste before it hits the impeller of a pump (which would then chop it up). I want to minimize the amount of large waste because it will get caught in the hydroponic system. The hydroponic system will not go in until spring 2016. It's just a "black box" in my head right now. Water comes in, water flows out.

Skimmer: I did not include a skimmer because I was under the impression it was not mandatory (since I plan on covering the pond). But now I will research it. Thanks!

Winterizing: I’m told that as long as the pond is two feet deep (and an aerator keeps part of the surface from freezing) the fish will be OK. My town considers any body of water over 24” to be a pool (and a pool owner must follow several codes). So, my pond will be 23.9” deep ;-)

Shelves: Not under the liner. I’ll probably suspend a few small shelves from the top.

Aeration: I thought the waterfall would be enough. No?

Number of fish: Will be determined by the volume of water in the pond. I’m not quite done digging so I don’t know. I’ll probably get the optimum number of fish (based on water volume and average size of adult fish) + 1, (knowing that at least one will not survive).

Thanks for your time!

 

[addy1]

Welcome mr whitehat hacker!

Sounds like a neat pond to be. I tried gravity flow , in a previous pond, made some mistakes , i.e. it did not work. Not enough water, gravity flowing in to match the water pump sucked out So make sure your inflow is big enough to handle the pumps draw.

A good waterfall will put in some great aeration. I only use waterfalls for aeration.

Just a suggestion, unless you are really stuck on koi, I would suggest you get some shubunkins, goldfish. To me shubbies are as pretty as koi easier to care for, more forgiving about water, handle winter better. Your pond is not real big, it could handle one or two koi (per what I read on here) . I have a 1000 gallon stock tank that is part of my pond system, it has a bunch of shubbies in it they are really pretty. My big pond has shubbies in it also. Some call them poor man's koi, lol,
I can afford koi, just don't want to bother with them.

Also if you want plants in your pond the koi will eat them up, most of the time.

 

[DrCase]

I would add a skimmer , you could tie it into your bottom drain line.
A few valves to control the flow would be helpful
Maybe a 2nd water return below the pond level

 

[Dave 54]

Hi Craig welcome to the forum we are what is termed true koi keepers with a formal pond deviod of plants we Brits dont believe in plants and koi love to eat them .
You want a koi pond that isnt that hands on sadly with koi they are prodigious producers of detritus so you need a good filter on the pond.
We brits normally go about fitting a 4" bottom drain part way down from there we place a 4" slide valve this is to cut off the pnd when doing filter maintenance then opened and shut to viod any large detritus that has gathered in the bottomdrain, the filters are gravity fed, four in number with Jap matting and quilt batting in two of the three filters the first being a settlement chamber , the last full of k1, aqua one bio balls , that but not least bio chips .
There are three airstones in the second and third filters six in the last and these are powered by an airtec 40e air pump , the bubbler bottom drain cover is supplied by another 40e via an air hose and the pump that powers the whole pond is an Oase 3500 , last but not least we have a 36watt UV/C maintenance is done on a monthly basis water changes weekly .
I hope this helps

Dave

 

[mgmine]

Your pond is 1500 gallons so that means you want a pump big enough to turn it over once an hour or so. Given that your boxes won't be able to handle the volume that the pump is putting out as Addy1 pointed out. Putting that aside all those boxes will be more work than is necessary. A simple skippy filter tied into a water fall is all that is needed. I would definitely put in a skimmer if for no other reason it's a good place to put your pump, but it will involve some engineering to get it into the wooden walls you will need additional space behind the wall to bury the back of the skimmer in. As far as the bottom drain there is no reason for one and it will just be something more to go wrong.

 

[Tula]

Welcome I don't think your pond plans are deep enough for your winter climate. I know you mentioned town codes, can you look into what would be necessary to go deeper?

 

[Nepen]

Since you mentioned hydroponic, I would suggest having a bog as extra filter. Some of us here have bog as filteration. We just put pea gravel in a large area and water come up through them and go back to the pond via water fall, this way you can use it as both filter and hydroponic. I plant basil in my bog, will add some other plants next year.

 

[Mmathis]

Since you mentioned hydroponic, I would suggest having a bog as extra filter. Some of us here have bog as filteration. We just put pea gravel in a large area and water come up through them and go back to the pond via water fall, this way you can use it as both filter and hydroponic. I plant basil in my bog, will add some other plants next year.

Good idea! And bogs can be so pretty!

 

[Nepen]

Since you mentioned hydroponic, I would suggest having a bog as extra filter. Some of us here have bog as filteration. We just put pea gravel in a large area and water come up through them and go back to the pond via water fall, this way you can use it as both filter and hydroponic. I plant basil in my bog, will add some other plants next year.

I just want to add that I see potential bog filter, just build it up next to the pond itself, a little higher, then the water will just flow right back to the pond. and no need to dig!