I'm enlarging my pond...finally! I'm so excited about this. What I'm agonizing over is the transition. I have a 300-400 gallon preformed pond. In this pond, I have 30 Japanese snails (and their recent babies), 11 goldfish (and their recent babies), plants and one HUGE bullfrog. I'm excavating this pond and using the same spot for the 1500 gallon larger one. Any tips on how to transition with the least amount of stress and life loss would be greatly appreciated....I do have the help of 4 very strong men! ;)"

I just went through the very same process. Gather all life to be saved and transfer to some large plastic storage containers. I divided the fish and plants amongst 3- 50 gal.containers. I used a small fountain pump in the fish containers to cycle and aerate the water. I also put plenty of floating plants in the containers with the fish to help with additional shade. I put a top net and some shade cloth to also help with the temperature. Some melafix and stress coat was added to try to help the fish in anyway possible. All fish survived fine and have been transferred to the larger pond today...so hopefully all goes well. Sorry for the long winded post, hope it helps you!

How long were fish out of water, so to speak?

In my mind (I don't know if this will work in actuality though), I want to pump out the water in the pre-feb pond - down to a few inches. Lift it out, keeping all life intact and set to the side. Refill, hook the pump w/filter back up. Finish enlarging the pond...here's where things get tricky. After filling new pond, how fast can I cycle it to get the fish transplanted?

Can I use the original pump w/filter (it's submerged with bio-balls) to do this more quickly?

Can I take a % of the water out of the pre-fab and put it into the new pond to cycle quicker?

Of course, I'd like to have this done in a weekend...we're weekend warriors! But in the end, I want the maximum amount of aquatic survival.

Krazyvan answered your question almost exactly as I would have. Thanks for saving me some time!

You can try to lift the old pond out but I expect it may become stuck. Also, there will be the most gunk on the bottom which is not great for the animals to sit in. So, I suggest removing and netting out the larger animals or at least those you can easily get. Then, you can pull the pond out with the more stubborn animals down in the bottom gunk. I suggest using kiddie pools or plastic storage tubs to save water from the old pond to refill it when you set it aside. If you stir up too much stuff in the old pond, and it's too dirty, you'll want to clean it all the way out. See http://www.fishpondinfo.com/myfish/clean.htm for how I clean out my 153 gallon pond. In your case, you're cleaning your old pond and setting it back up while the new pond is being made.

Once the new pond is ready, fill it up and run the new pump and filter for a day and aerate the new pond well. Be sure to add dechlorinator if you have city water and maybe a little pond salt (0.05% at most). Then, the animals and plants can go right into the new pond which can't cycle until they are in there. Put the old filter's bioballs into a bag in the new filter so it's innoculated with the good bacteria.

If you're in a rush, you can do the above in a day but aerate the new pond water heavily for at least two hours before putting in fish. See http://www.fishpondinfo.com/fishcare/water.htm#gas for the reason why you need to aerate.

Adding water from the old pond to the new pond won't help it cycle much faster as the nitrifying bacteria are attached to surfaces (bioballs, side of the pond, plants, etc.) and not so much in the water itself. Adding the old water will introduce the microlife that was in your old pond such as microorganisms, algae, and any bad stuff too. I wouldn't bother putting in the old water.

Good luck!