It'd be better if you seeded your tank with another established tank's gravel or filter. The water actually won't have much bacteria in it.

Gravel from another tank or part of another tanks filtration would be the best, the bacteria lives on surfaces, it doesn't really float around in the water. Also your pond water may have some diseases that would be harmful to tropical fish.

i use the fishless method for my last tank and it worked really well. I just put regular ammonia in the water to 4-5 ppm and let it run through the filter I tested the water every day and when the ammonia dropped I would add more. Once the nitrites started I cut back on the ammonia to 2-4 ppm and let that go. The nitrates were off the scale for the last couple of days but with no fish it was easy and I didn't have to change the water at all until the cycel was complete. The whole thing took about 2-3 weeks before I could add fish but when they arrived they have been healthy and the water has tested well since. I also use balance by tetra for the nitrates.

Hello there

You must use filter material and some substrate from a healthy FW tank.
I can tell you for sure you will be importing some nasties into your new set up if you use anything from your pond.

I set up a 5ft FW tank from a cracked 4ft FW tank.
I saved as much water as possible all my filter wool (even though I did not require it in the 5ft) I washed all the substrate and stored it with the wool & fish in large containers until my new tank arrived about 4 weeks (an insurance claim)

I set up the new tank using all the old base plus new base, & existing water. Also a new power filter. I added some of my old filter wool to start off the bacteria in the new filter. I also added the recommended Sera Bio Starter

The fish were added straight away.
Every second day I was adding a bacteria powder to kick off the bacteria.

I never lost a fish the water was checked every third day and never a problem.

Some say it can not be done well it can but I have had 35+ years with Aquariums and I can assure that tank had some very valuable fish in it and they are still with me.

After every filter pull down (now a large Eheim Canister)I add the recommended dose of Sera Bio Starter I also do this at every 15% water change.
Without going into the chemistery of it, this keep the good bacteria in its origional healthy state. More work more cost but a better tank over all.

I will send you more info via a personal E/m

Keith

It would not be a good idea to use pond water to start your new tank primarily because of the potential for nasties to get in. Of course if you're setting up a native tank, pond water may be the way to go. Puddlemaker's suggestion to use amonia (be sure it is NOT scented ONLY plain) has at least 3 good things recommending it. First, one does't need to purchase 'throw away' fish. That is, fish purchased with the main intent to aid in the development of a bacteria colony. Second, given it will take at least 3 weeks to get the water parameters (you will be testing, right?) set up you'll have a little extra time to arrange whatever decorations you have to suit you. Finally, if going for a planted aquarium, the plants will likely take off much earlier than in an established tank. Start with small plants to avoid competition with the bac colony. Both will be competing for the amonia and nitrites. Of course you could always go with just plants and avoid fish - kindova a plant garden without critters.