I need a little insight on water changes in a pond.

I have a 300 gallon prefab in ground pond and had 8 fish (Comets & Shebunkins) until 4 were taken by a hungry Crane a few weeks ago.

I have never taken any water out just for the sake of changing water. Twice a year I shop vac all the gravel out with my 20 Gallon vac and it takes 3 or 4 loads before I suck all the gravel up. So maybe I remove 80 gallons twice a year. Wash the gravel and put it back in, then top the pond up. So far in 3 years I have lost no established fish. I lost 2 very small comet that my wife got but to be honest they looked sick when we got them (should have QT them) but they died within a week of going in the pond. I have lost 8 fish to predators 1 to a cat and 7 to birds.

I started with 6 and had as many as 8 and I think that I could go to 12 and be okay. I have 300 gph filtration and 600 gph through a water fall. I test the water every weekend during the summer and only add water as needed to keep the pond full.

My water does cycle and I can see the fish react to changes but it seems to self regulate. The fish are all growing my biggest was Big Bob at just over 8" and 3 years old (he was one of the ones taken over New Years). So the water has not stunted any of the fish.

So the question is what I'm I missing and am I just lucky not to have lost all of them due to some water illness?

You should do about 10% water change a week. Your twice a year clean out with the shop vac is maintenance that also has to be done. I clean mine out twice a year as well with a pool vacuum. The 10% water change basically (from what I understand) puts back minerals into your pond that are in the water. When you go so long without water changes these minerals are eventually leeched out of the water. The fish need them for good health. There are things you can put into your pond that are all natural that would help the health of your fish, but the 10% water change will do just fine.


You have one pump turning the water over once per hour and another doing it twice an hour. I'm also thinking you have a good bio filter as well. The ugly bacteria likes water that doesn't have so much aeration, that's why it grows so well in the gunk in the bottom of your pond. I bet your pond is saturated in oxygen! That is something a lot of people don't have enough of in their ponds and thus they get into trouble.

Sounds to me you have a great set up. Sorry about the losses though, I 've never had bird troubles but I have lost 5 to cats. I don't much care for cats . I just noticed you live up north! I love Coeur d'Alene, one of the prettiest places in the U.S. next to Hawaii. Your lucky!

Post pics of your pond if you can, everyone here enjoy's to look at pond and fish pictures.

And welcome to the board

Scott

window screen from homedepot or a pond net cover will keep animals from getting to your fish