Anyone else have an outdoor fish pond?

House came with an outdoor pond. I stocked it with koi, shubunkins, red caps, comet and Chinese algae eaters. One side (two level pond) has become pretty murky but has a bio/mechanical filter on it.. Anyone have tips? 

Yes. but only goldfish left and tadpoles from the Leopard Frogs. Raccoons ate my 10 year old koi. I was heartbroken and never replaced them. The goldfish are having babies though. I try not to get excited because I know eventually those @#$% racoon will get them, too. Or the frogs. Your algae eaters are tropical and will not survive the winter. You carp-type will hibernate. (Stop feeding them in October) We had a plechostomus for many years. Brought into the aquarium for the winter. Eventually it got so large a pet store kept it for me. I think the raccoons got it too. Cuz one day, it was gone. 

Tink, can't you put a screen over that to keep them out of there??

Oy 

Hmmm I've never considered the racoons getting at them. The koi are getting quite friendly, so I hope they're ok. We have had some very large broad banded water snakes around, and another smaller one that I witnessed grab a small goldfish. There's an armadillo and opossum (sometimes drinks from the pond) around often but I don't think they'll go for a fish. There are often great blue herons and night herons close by, but I think they prefer to stay away as long as they have food elsewhere 

We had a Small Green Heron sit on the fence for days watching my koi. Finally got one and dropped it in the flower need where it died. Had aGreat Heron in our yard. Scared the dickens out of me. He was huuuuge! Weeks life seems perry lazy around here. The raccoons are my main menace though. The koi were 12" long after 10 yrs. And friendly too. They were smart. They hid in tunnels i provided. But the raccoons lifted the tunnels up and chased them. Not only were my fish gone, but the pond plants were ruined. Once i put a wire mesh over the top. The raccoon stood on it. When a fish would swim through to the top, he nabbed it. I give up. Now it's only 25 cent good fish in the pond. And i still feel bad when they disappear. I don't always have the guts for Mother Nature. Oh, and i have had the raccoons in my attic too! Grrrrrrr! #$%&! 

I have water about 30' off my back deck, so there are blue herons, white egrets, many others daily. They are huge :) baby ducks have been out practicing swimming the last few weeks, and occasionally come up on the lawn. 

^ yes to all what tink said. We chose not to put in a koi pond after having one in another state. I transported my koi 10(all at least 20 to 24 inches) to my brothers ponds 4 hours away. First you need to check the bio filter. Your pond may have these brushes part of the filtering system in the pump. It needs to be cleaned out. Our pond was 10 feet by 5 feet and about 4 feet in depth. I don't know the gallons. We could only sustain 12 large koi and a turtle(few babies). You could build a pergola over the top and double uv screen. It helps with algae and with birds. Raccoons got my koi I gave to my brother:( it took them awhile but his pond was only 2 to 3 feet deep. You will have problems with other things eating your small fish, snakes etc. Once you get your koi pretty big and they start to mate you need to look and hear for splashing. It would wake me up at night. I thought something got in the pond. Over the next few days the pond is frothy. You need to take a panty hose stretch over a small net and scoop out the froth, eggs. Other wise you will over load your pond. You won't get all of them. Picking out KOI you want babies with 2 colors. When I say 2 colors make sure large pattern of cilor. As they grow colors stretch and they loose the pattern. Look for a colored head. My favorite KOI which was my biggest. We called her Goldie. She was solid gold. She would come up and let you feed her out of your hand. The kids would put their feet in the pond and she would nibble their toes. Gently. God luck with your koi pond. 

By the way do not mix bass with your KOI. Our friends did and they killed all their KOI. 

Tink - put a few arch shaped rocks in your pond for the fish to hide under. (Just read that you said you had tunnels...those stinkin raccoons!)

Fuzz - for the algae get a couple barley straw bales and throw them in the pond. You can get the barley bales from Kingwood Garden Center locally or order them online. 

Crafty, thanks. I did get some barley straws online. I didn't know you could find them in KW. Does the garden center have other pond supplies like plants? I'm thinking of making a plant filter, running water from the pump through the roots in a place where the fish won't eat them 

Fuzz - I'm not sure if they have pond plants. Since I live in Kingwood my dad asks me to pick up barley straw occasionally when I'm coming to his house. :) 

I had a neighbor that had a Koi pond and the snakes loved it! When they decided to rest in my yard, I put out some Snake-Away! They were bad. 

Racoons, check. Possums, check. Snakes, double check. No more pond now. 

Cover the pond with chicken wire. We even have guppies in one but you will
have to heat in winter if you want to keep tropicals and the algae eaters. 

My friend has one. About 12x12 x2 with these garbage can sized barrels filled with plastic straw for bio filtration. Plus uv lights. He has about 50 koi. A few get killed every now and then by cats and birds.