Haven't been in this section before but ..........
my neighbour is re-doing his garden and no longer wants his pond. It's one of those rigid plastic moulds, dug into the ground. If I take it I want to have lots of plants and only a few small goldies. Also, he has some newts and frogs which I would want to keep, too.
He says that with an outdoor pond beyond a certain size a filter isn't necessary and he only has a pump to keep the water oxygenated - I'm not convinced that this would be right for GF so thought I'd ask.
Can someone confirm what size a pond has to be not to need filtration? Assuming I do need it, what type of system would be best.
Thanks
Pixie
PS It's not very helpful I know, but I'm not yet sure what the capacity is; he was going to check and get back to me.

Theres a thread somewhere in here about loz's pond and that is filtered and has extra oxygen in it so i reckon if youre going to add goldies then it will need a filter in it.
Im not that great with ponds so im sure someone will be along soon to help.
If the pond is less than 3.5 foot deep then you will need to over winter the fish.

If you are going to keep fish in the pond, and if you want to keep the fish and pond healthy you need filtration with pump.

With pump at least they will have oxygen, but it would be like living in Los Angeles on a bad smog day every day. Not good.

Those plastic preform ponds are usually only about 18-24" deep and the largest they come is 264 gallons (I used to sell them!). They are good but are very limiting. However if you only want to have goldfish then you should be fine.

You will definitely need some sort of filtration if you are going to have fish, just like in a tank. You generally want to circulate half of the pond's volume per hour. There are a lot of good pond filters out on the market. You will also need a pump to run the filter. That is where you make sure it is rated for your pond volume.

As a side note I would worry about the GF trying to eat the newts and frogs as they get bigger. Mine cleared out an entire pond of tadpoles in a few days.

OK all, thanks for input. The capacity it turns out is only around 75 gals so I think I'll hold off for now.
I've been thinking that if I am going to go to the trouble of digging out a pond it would be tempting to really go for broke and build koi pond........
Not something to be undertaken casually, I'm sure. Which are good info resources for this?
I feel obsessive planning coming on; maybe my husband might divorce me?

The best resource is Peter Waddington (his books are deffinately for the obsessive), he is the koi god. After him you can go to koivet.com, koiphen.com, koi.com, Bonnie Hale @ Bonniesplants.com, koicarp.com and so on. Peter Waddington wrote the book 'Koi Kichi' and then followed it up with 'Koi Kichi 2' they are both very good.

You made the right choice. If you know your going to want a bigger pond your wasting time and money on a smaller one. When it comes to ponds build bigger than what you think you'll want and you'll be happy (even though you'll still want bigger).

Scott

Thanks for all this info, Scott. Information gathering will begin tonight........