as you can see from my previous thread i have started digging my pond, wasn't going to have one at this house but what the heck...life's too short!

i haven't made any decisions yet as regards to type of fish or anything as i'm just waiting until i see how big i can dig the pond out as our garden seems to be a pile of boulders and rubble covered with 6inches of topsoil

so what i'm wanting to know is how many goldfish or how many koi can you keep either worked out in terms of gallons or surface area?

Also how many times per hour should a filter&pump pull the water through for each type of fish...is it 10x like for goldfish tanks or less than that?

Thanks
Jamoko

In a pond you want to circulate the water once every two hours. I like to go a bit above that though, and especially if you are going to have koi.

Ideally you should have about a thousand gallons per koi and the minimum pond depth would be 3 feet. When I was digging mine out last summer it was going to be about 2,000 gallons and almost 4 feet deep. Really it was already too small for my goldfish and two koi who were going in.

For goldfish you want about 20 gallons each, just like in a tank. If you can give them more than that, so much the better!

I sympathize with you about digging, though! Our first pond was in very firm soil. At this house though, our soil is honestly just sand, which is why I dug the whole thing out so quickly, and then it collapsed because the ground was so soft. So be glad you have hard dirt, at least!

Thanks for the advice, mmm at that rate i doubt i cold keep very many koi, so perhaps more goldfish will be the way to go but i'll not make any decision until the pond is filled and gallons calculated!

jamoko

1,000 gallons is nice, but 240 gallons per koi is fine. You need to make sure you have good filtration and as js stated depth is important. Don't go cheap on what you build your pond with and you'll be happy with it. If you skimp don't skimp on the pump and filter that is the heart of your system. External pumps are going to cost up front but they are more effecient, which means they'll save you money in the long run. Also too much filtration is better than not enough. More is always better.

Scott

thanks for your reply scott, i followed your link to your pond pics... what can i say...i'm lost for words, it is absolutely beautiful! i like the hard lines along the edges, thats the kind of look i'm hoping to acheive with having my pond at the edge of my decking. You have some absolutely gorgeous big koi there too!

I seem to be getting different information regarding stocking levels everywhere i turn as i was speaking to a family friend yesterday, and he has a 1500L (400gallon) koi pond with a good filter system with 12 healthy koi in it, so that means each fish has approximately 33 gals each.

He also told me that for a koi pond your supossed to have a filter 1/3 the size of your pond which explains the huge filters i've seen online and in my local pond supplies place...is it really necessary to have such a big filter of is a smaller one with a high turnover do just as well.

what type of filter system do you have on your pond scott and what is your hourly turnover?

thanks again

jamoko

You need a big filter for a koi pond. The more fish you have the bigger filter you need, the more bio media the more surface area there is for the good bacteria to grow. Also, when you have faster flow rater you also need larger filter with more bio media because when you are sending your water through the fitler faster you are also knocking bacteria off the bio media.

You certainly can keep a overstocked pond healthy, it's been done. The problem is the more fish you have in an overstocked system the harder it is to keep your water healthy for your fish. But it's not impossible. The thing is when you overstock it's too easy for your perameters to get out of wack and once it happens things could get bad fast. If you stay with the suggested stocking levels it will be easier to keep your pond chemistry under control.

Another thing to look at is these fish can get up to three foot long. In a small system where the pond keeper keeps the water perfect is a three foot long fish going to be happy?

I have approx. 4,000 gallons, a 1 horse power external pump with a large sand filter (don't know what size but it's big) that has been made into a bio filter using bio media and not sand. I keep my flow rate at around 4,000 gallons per hour but can bring it up over 8,000 gallons per hour. This pump is cool it came with a little computer and I can put it at any speed I like. I also have a 300 gallon bio falls which has two large bio mats in the bottom with four large bags of lava rock on top. I have more filteration than I need but remember when building your pond you want more than you need. If you have more you will always be safe. I also have a william lim stainless UV light, a skimmer, and two bottom drains.






BTW three weeks ago I was promoted at work and am in the process of moving. I have to give up my beautiful pond and it hasn't been easy.


Scott

scott, that must be heartbreaking having to leave that amazing pond...i just hope the new people moving into your house appreciate it as much as you do! thanks for all your information...you have an amazing setup there, i do realise that the pond i'm building will be classed as small, so i would be reluctant to try to keep even a couple of koi as i would want to do my best for them, but i'm treating this as valuable research because next time i move house provided i have the room i will want to create a proper koi pond!

thanks again and good luck with you move and promotion!

jamoko