Help: My pond is leaking after I power washed it.

[EAC]

Thanks for the verification! I appreciate it!

Both of the larger Gold/Orange ones are indeed Koi, which are carp (Same as Goldfish, just fancier) Here is a List of Koi Carp breeds, there are also Butterfly Koi which have long flowing fins.
These are Two Koi I have, the White Marble looking one has Blue tint to it now.

The List:

 

[EAC]

Got the exact measurements last night. It's 8.8 long, 3.5 wide and 2 feet deep. So, it looks like I'm around 500 gallons. I was way off with my original 180 gallon estimate!

 

[Jason]

Yeah, Mine is 10' long, 8' wide and 2' deepest and is around 500 gallons, If you get Koi, you will have to find a new home for them after a few years as they get very large (Over 2' long) unless you build or plan to build a larger 1,000 + gallon pond in the future like I am, but you can do Goldfish all day!

 

[Waterbug]

Even 500 gal and that size stream I would expect serious draw down. The shape of the pond also effects draw down. A 500 gal 1'x1' pond 65' deep could draw down 10'. While a 500 gal 5'x5' pond 2.5' deep might only draw down a few inches with the same stream.

In either case, because of the pond and stream size, and because you say the leak appears and disappears, my first suspect is draw down and not an actual leak. I'd start there any ways because it's easy to check.

 

[EAC]

The level has held steady for 4 days now. I think the waterfall used up alot of that water. I have two 1 foot deep crevices built into the waterfall, so a good amount of water sits in there too.

Even 500 gal and that size stream I would expect serious draw down. The shape of the pond also effects draw down. A 500 gal 1'x1' pond 65' deep could draw down 10'. While a 500 gal 5'x5' pond 2.5' deep might only draw down a few inches with the same stream.

In either case, because of the pond and stream size, and because you say the leak appears and disappears, my first suspect is draw down and not an actual leak. I'd start there any ways because it's easy to check.