Question
Hi john, I have no knowledge on breeding, but a couple of our fish look pregnant. I am not even sure what they would look like! Also we are finding it really hard to keep the pond clear/clean. After a water change it is only staying clear for about 2 days, then going bright green. Please help!

Answer
Vikki,

They may be pregnant.  Spawning activity usually includes a lot of chasing around and jumping.

From you description of the green water, you may be over feeding which could also cause the fish to be fat.

A simplified formula for green water goes like this.

NUTRIENTS INTO THE WATER = GREEN WATER
NUTRIENTS OUT OF THE WATER = CLEAR WATER

To get nutrients out of the water, you first have to add a layer of large gravel to the bottom and line the sides with larger rock if possible.  This is the home for your beneficial bacteria to live.  Add a pump that will turn the water in the pond at least once an hour, even more is better.  This moves the wastes passed the bacteria and furnishes them with oxygen.  Pump needs to run 24/7.  Add a good quality bacteria concentrate to jump start your bacteria numbers.  Add floating plants.  These remove the nutrients after the bacteria converts the wastes to nitrates.  Good plants are water hyacinth, water lettuce, parrot's feather. Any plant that floats in the water and draws nutrients directly from the water is good.

Now that we've got the mechanism in place to remove nutrients, let's stop adding them.  No fish food for a couple of weeks.  They won't starve, let them eat algae or nibble on the plants.  And stop changing the water.  Every time you change the water you add more nutrients.  Get everything set up then let it work.  Expect the water to turn green halfway through the process.  After the bacteria and plants take over the water will clear and stay clear.

Hope this helps,

John