The general rule of thumb is 250 gallons per koi, 150 gallons per goldfish, regardless of their size. Little koi quickly become big koi, ;-)

One thing to consider when you're doing your water volume calculations - I would suggest using the inner edge of your shelf rather than the outer edge of the pond when doing the measurements. Shelves greatly reduce the number of gallons, and many people have thought they had more water than they actually do because they measured from the outer edge without taking the shelves into consideration.

Nancy, thank you, I hadn't even thought of the shelves like that. Right now I try to make up for the space the plants/pots take up in my existing pond, but what a dope..never thought of the shelves! Thank you! Time to recalculate my gallons for the new pond!
I can't wait for my Koi to get bigger :) I just want to get 1 more, 2 max so he isn't lonely...at this rate, he may start thinking he's a goldfish, lol.

If you are considering koi, please try to get a minimum pond size of 1000 gallons and stock at a rate of at least 250 gallons per koi. Also realize that when a filter manufactures says a filter is OK for 1000 gallons, it really isn't. Double the filter size and you should be OK. I also agree with the plant shelves....I don't like them. They take up pond space. I'd rather set the plants on milk crates or even those little plastic patio end tables. They are inexpensive and come in dark green....you can't even see them in the pond. they give the fish a nice place to hide also.

Some like shelves and some don't. We're a big fan of shelves. If you do dig your shelf deep and wide enough,
you then can load it up with rocks and plants. The plus side is there is a place for plants (in between the rocks)
and also no liner is showing and the pond looks natural. like a real pond in nature.

The rocks here are all piled up on the shelf. This photo is from June. We constantly move the rocks and plants around (nothing is cemented in) to make room for plants.
some plants are planted bare root and some in pots.

This is the dog leg section of our pond. It is approximately 6 x 13 ...we added this section on to the existing pond the second year.
I suggest you go bigger, as koi need more room and they like to swim...
You also need a section that is at least 3 feet deep for the fish to overwinter. We have a 3 1/2 foot section and the rest is about 2 feet.
Also after you install the liner, don't cut away any excess liner, roll it under and place rocks on top of it.
The following year after we put in our pond, we removed some rocks and dug a little move and made a beach and bump-outs around the pond. (the excess liner allowed us to do this. It gave a more interesting look to the pond.
Have you given any thought to a bottom drain? If not read up on bottom drains, the purpose of a bottom drain is to continusally re-circulate the pond water through a filter system and return it back to the pond.

If you have the room, I would consider going bigger if you want koi.

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This is the same section, last July

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This is an artists drawing of the shelf (only we used flat rock on the shelves and round rock at the top)

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I am speaking as the person who is about to add a second LARGER pond just for my koi: you should always go bigger and deeper than you might think you want. I have a 7x11 pond (2 ft. deep) and it is not long, wide, or deep enough for koi IMHO (but just fine for my goldfish). I'd start with at least 3" depth and maybe go to 4" at the bottom drain so that the koi have plenty of vertical as well as horizontal room to swim. This will help their body confirmation as they grow larger. My new koi pond will have 5 - 6' foot depth and two bottom drains. Be sure to have adequate current in the pond to aid their development as well.

You are SO right zoenipp. My current big pond is 4' deep and 9000 gallons and it's not big enough. I am planning a new one....this one will be 7' to 8' deep and around 18,000 gallons. A large collection of 30" koi is breath taking to see and you need a big pond for that. But a pond that size means a serious committment to this hobby. I have found though, the bigger the pond, the easier they are to maintain. Everything is so stable, from water temperature to pH.

Thanks for the opinions so far.

cliff_and_joann, that is beautiful! Nice job! If I use a bottom drain..where would the pump go?

Like I said, I don't plan on having a large collection of Koi..most likely 2..3 MAX. You all honeslty don't think that 11x7x3 isn't big enough for 2 Koi?

My liner I have is only 16x18, and we rent right now. I am doing this in a yard that isnt even really mine..but I live here in this house, and I want this so I am doing it. This whole set-up is only temporary as I will be taking it all with me when we buy a house. (that should be fun!) When we do that, I can go bigger with a pond. Plus I have 3 kids, and dogs who really don't want me hogging the whole yard, lol. They complain I take up too much of it already. They are excited about this bigger pond though, and have even suggested I put it smack dab in the middle of the yard.

Ccoombs, My pond will def be over 1000 gallons, almost 2. I thought about no shelves, but I really want marginals in there to help hide the liner. I don't want the rock outline, of course I will have some, but I want plants to mostly hide the liner.

That slope/ledge idea was in part of my plans, for the front length of the pond, I'm just not sure about it..I'll probably wind up doing it though. That drawing is pretty much how one of mine was, minus the bottom drain.

Ok Danielle, This puts a different slant on things.
Since your in a rented situation, I suggest you keep it simple. Whatever you do, you have to undo when you move.

You can manage 2 koi in 11 x 7...I would rethink the goldfish however, as they multiply like crazy. The purpose of the bottom drain is to filter the water out through the bottom drain and into a filter system outside the pond.
It can be a DIY system, it doesn't have to be expensive. Our system is gravity fed. The filter tubs house the pumps and the filter material which traps the fish waste.
We have 3 tubs because of the size of our pond, however it can be done with one tub in a smaller pond.
I provided the link to our system, this is only one way that it can be done. I hope others can chime in here with how their system works with bottom drains.

Joann

Here is a link that might be useful: DIY pond plans and filter system

Danielle, if you stick to longfin koi, you could easily get by with 3 if you are going to be over 1000 gallons. Longfins do not get as big as standard koi and seem to grow slower overall. A bottom drain is a wonderful thing to have. You will never have to vacuum the bottom of the pond! All the fish poop and uneaten food is carried away to the filters. In a gravity fed system, the pump is usually placed at the end of the filtration and pumps the clean water back to the pond. The one key to keep in mind is the filters must be set into the ground so that the water level in the filter is the same as the water level in the pond.

OMG, what did i get myself into? my Huge 125 gal pond couldnt even supply a small water change for you people. I wasnt planning on quiting my job i just wanted to have a pond with some fishies and some relaxing noises. Is this what i have to look forward to? I'm gonna have to go and buy some private lakefront property so i can 1 up all of u. Only kidding but still?????
Mike

OK, so go ahead and yell at me, but I think I am going to skip the bottom drain for this one. Never mind the fact that if I had more than 2 pumps going DH would drown me in the pond, lol. He's not happy about 2! When I go bigger I will do all that. I started digging the perimeter, I decided to do the plant shelves along the back only. mosquitos were swarming so I decided to come in and have a snack.
I'm a nervous wreck now that I am going to screw this up. I keep telling myself it's just like digging the holes for the preforms, only bigger..but I am nervous. Trying to dig at a 20-30 degree angle..what if we get a big rain and the damn walls collapse before the liner is in and filled?

lol Mike, my 9 yr old daughter just said to me earlier, while I was standing there stareing at the outline of the pond.."Why can't we just buy a house where there is a pond or lake already?"

Ccoombs, I know you are totally into Koi and your eyes will bulge when I say this, lol, but I can only get what PetCo has. I am not spending more than $20 on a fish. At PetCo, you get what they have and that's that, all the rejects, lol. I don't know what kind I have right now. He's got a few scars, but I don't mind. I picked him cuz he had the most white on him, & then I saw in the white of his left eye, he has the letters 'JR' in black. So cool. So that's his/her name. I'll try and post a pic of him/her later, right now I can't get into photobucket. Wish I could get a pic of his eye..but he doesn't seem to want to pose for me, lol.

Thanks for all the advice so far guys..I really appreciate it.

Mike,

LOL.. I am with you. My pond is 160 gals and, though I would love a larger one, it's not going to happen. So to read about people with an 8' deep pond, 18,000 gals. hahaha Well, I am just amazed.

Anne

Lol...I was that way not many years ago. I was quite content with my little water garden. And then I went to a koi show and saw these show tanks with the most amazing creatures I have ever seen...big beautiful fish, some well over 36" long. I knew that was what I wanted. The first time I spent over $100 on a fish I thought my DH was gonna have a cow!! And now....he's worse than me! I hate to admit this, but I have a fish living with the breeder in New Jersey for a couple of years to get the benefits of spending summers growing in an earthen pond. I had to make payments on that fish. But she is SO pretty......

(I got it bad, don't I????)

Go as big and deep as you can!
Cliff and Joanns pond was my inspiration!
I studied bottom drains and decided to do the shelf with the rocks but everything else is bare liner.
Since mine is more of a watergarden and I heard that Koi love to eat plants, I have Sarassa and Shubunkin comets and Golden Orfe instead.

Every time, I see Koi, I am so tempted!!!!!!!!!! They are so beautiful!

Daniellalell,

My pond is 15 x 8 and has no bottom drain. If and when I decide to go bigger, I will definitely give serious consideration to installing one because of the ease in caring for the pond and keeping it clean. You can use a shop vac to vacuum the bottom, and you can build a skippy filter or a trash can filter.

You can easily keep your two or three koi in a 1000 gal pond. Check with some local ponding dealers. Many have smaller koi for as low as $10, say 4" to 6" in size. You can still get those fairly decent koi without breaking your pocketbook. I wish you lived here in Tulsa! I have some koi babies I'd let you have for free, LOL.

I do have a skippy on my existing pond, and am tempted to add one to the larger pond..but would I put it before or after the pressurized bio-filter?

O Nancy don't tease me like that! LOL! When you use the shop vac to vac the bottom does the pool need to be mostly drained? I read about vaccuming ponds, but I don't quite get it. Does it HAVE to be done? I am pretty obsessive now with my smaller pond about skimming the surface, I know I will be the same with the larger one..I think I need a longer net now though, lol. Can I just net the stuff out of the bottom? My Koi I have now I paid $17 for. He was the largest PetCo carries. I did give my name and number to the fish people there though since sometimes people give up their fish to them, and they can be adopted for free.

Joann, I have seen your pages & photos before when I first started reading and researching about ponds last August. I am so jealous. Your yard is an inspiration to say the least. I can only hope someday i will have something half as beautiful!

OMG Ccoombs, yeah you got it BAD!! LMAO! Where in Jersey is the breeder, if you don't mind me asking? I won't ever dare to go there, lol! I hope my DH gets into the pond thing as much as me..he's coming along, after all he just got me the stuff for the bigger pond for my Bday, which is tomorrow. He won't help dig tho, I'm not complaining, I don't want anyone to, lol.

1sst, so you don't have a bottom drain? I have waterlilies, and lots of plants in my ponds, but the Koi so far hasn't messed with them. He does love the water cress, but it grows so fast I count on him to eat it! It's like The Blob..taking over everything, lol.

Well, so far I have dug about 10"..have the mound for the waterfall & stream, which I wasn't planning on, but of course I got carried away, & the filter is in the ground. Gotta get out there nice n early tomorrow to dig more before it gets too hot.

Thanks again everyone!

Danielle,

If you find a local koi/watergarden club in your area, you can get cull fish from members at a very good price (or free) which will be nicer and healthier than what you would buy at Petco or Petsmart. That was the beginning of the obsession for me. . . Now I've been giving away most of my "cull mutts", getting ready to invest in some better fish for the new pond. Please think about that extra foot (to make it 4' at the deepest point). Your fish will thank you for it. The deeper the pond, the harder for herons to pick off your fish as well.

Longfins do not get as big as standard koi and seem to grow slower overall.

They do get quite large. My MIL has 3 longfins in the 30" range, not including the fins.

You do want to keep in mind, the more shallow the pond, the more of it will freeze in the winter and freeze your fish. You need some depth to get them through the winter.

Sorry, I was not clear. I have two bottom drains.

I have heard of some Koi leaving plants alone but with my luck, I would get ones that would turn my plants into a salad bar! LOL

daniellalell, my favorite breeder is Quality Koi. They are producing some real world class fish!! Here's a link.

Here is a link that might be useful: Quality Koi

O OK 1sst, thanks for clarifying.

Zoenipp, I didn't know that..thatnks for that DANGEROUS information, lol. I wish I could go 4'..I just can't right now. Like I said, in the future when I have my own house..O Geez..watch out..I'll probably be a Ccoombs Jr, lol.

Ccoombs, thanks for the link..They aren't too close, which for now is a good thing, lol. Wow, what a farm, that overhead shot is amazing. Gonna have to check into that mroe later on.

Hoovb, yes I know, thank you. That is why I am going to 3'. I don't think it'll freeze more than a couple of inches here..esp with the way winters have been getting progressively warmer. Our local ice skating pond hasnt frozen enuf to skate on in more than 10 years..they had to build a skating rink. Even our local little ponds dont freeze more than a couple inches for a day or so.

hoovb, I would love it if you would post some pictures of those longfins!! Longfins that big are REALLY uncommon! I have been to many koi shows and I think the biggest one I ever saw was maybe 26" (just her body) and she was 18 years old. She was amazing.

My rule of thumb for amount of fish is to have 1" of fish for every 1 cubic foot of pond surface area. You don't want your fish to be too crowded!

Here is a link that might be useful: Fish answers

danielle..Check out the link below..My neighbors pond..1500 gallons...no bottom drain..huge koi..bare liner..uv light..cleans filters everyday..bleaches pond once a year..and vacuums bottom..he's been ponding for over 30 years....enjoy!...Dave

Here is a link that might be useful: Awesome Koi

Just a thought but, you will be happy if you add shelves. they will be much needed when you need to climb into the 3 foot deep pit to rearrange plants, clean, etc. Unless you want to take a ladder in with you, or can jump like a deer you'll have to get out somehow, and viola!. Do becareful though when stepping on the shelves as they may not look it they are probably going to be very slippery.
As far as how big, go as big as you can afford. Once its all finished, youll wish it was twice as big anyway haha.

Hi there I am new on here but have found the info valuable so far so thanks to all.
I think we have just made a HUGE mistake with our new pond.
We originally dug a pond 6ft by 9 ft by 2ft deep and kept seven goldfish in it which wintered well and seemed happy.
Being bitten by the fishkeeping bug we then dug a larger pond on the raised area above the original pond which is 15ft by 20ft but we miscalculated the depth. We originally planned 2ft 6" but when it was filled we realised it was less than two feet deep. By this time we had moved the fish into place and have been given two smalll koi and three Golden orfe along with another bucket full of goldfish so 29 in all.
The water surface is plentiful but i am worried about the lack of depth. We have a large rubber liner in it which is now trimmed to size and rocked over and planted out around the edges. so to change this would mean a complete redig.
Has anybody any ideas whereas we could cut the middle out of the liner and dig the middle bit a lot deeper then join on a new piece of liner?
I think this could be an option. I dont want unhappy fish but my husband is groaning at the thought of rebuilding the whole thing.!

I think the main problem you will have in splicing another section of liner onto the existing liner is that there are bound to be folds in both pieces. It's difficult enough to get a good bond with a completely straight edge, and I think it would be even more difficult to get a strong seal with either tape or glue if there are folds in any area of the two pieces of liners. I don't know how you could get around that, and I don't think I would even want to try.

I think it would be easier and stronger in the long run to pull up the existing liner and start digging again. If you don't go any wider, I think you could work around most of the plants without too much damage to them.

Just my two cents worth, but I think splicing would only cause more problems in the long run.

Another option would be rehoming some of the fish and leaving the pond as is.

Yes fold in the existing liner was the problem that my husband picked up on. I have had some opinions from fellow pond owners that the fish may be fine as the water surface is plentiful and part of the pond actually flows under the 'Tikki Hut' decking at the side so they may be fine over the winter.
I am still very dubious about the depth and am just hopping to think a way around it without heaving out every single rock and plant - not to mention the filter systems under the grotto.

My koi spent their first year in my pond when it was about 22 inches in the deep end and 18 inches in the shallow end. They did just fine.

Thanks for that NancyM its made me feel a little more confident about the winter.
But you say your koi spent their FIRST year in a shallow pond - what happened after that.
I still have a sneaking feeling we will end up dismantling the whole thing and redigging.
Trouble is the longer we leave it the harder the job will be as the plants establish in the rocks.