Old and New Filter Cycling

Good Morning!
I'm learning fish the hard way, nobody ever said that having goldfish would be so difficult!
Ok here's my question, I've had my fish tank set up for a week, killed off 6 fish, changed 25% of the water and after many trips to the petstore and lots of learning, I have the ammonia down to 1.0.
I now know that I need to cycle the filter for 4-6 weeks before adding any fish.
What I'm wondering is...I have a filter a friend gave me used so I know it has been cycled. Can I clean the tank out, refill with water and fish and have both the old filter and new filter running and go ahead and add a few fish back into the tank? I figure the old filter will keep the tank clean while the new filter is breaking in?
My other question is how is the best way to clean the tank and get all the icky dead fish germs out so the new fish have a chance of surviving?

 

Since you already have ammonia in the tank, I would just run the old filter (from your friend) in it, and test daily until ammonia and nitrites are 0. Then, add a fish.

 

Cut and dry, you have to cycle the tank first if the fish are going to do well. Seeded is good but patience is the best. ;D

 

what size tank do you have? What kind of filter do you have?

Best way to clean out the "icky dead fish germs" is to let bacteria do it. There is bacteria living in your tank, on the gravel, decorations, glass, and filter. I wouldn't empty the tank and clean it that will just delay the tank being ready for fish.

I also second blackravens advice. Let the tank run without fish until ammonia and nitrite are 0 than you can add one fish. After that add one fish at a time spaced a week apart.

 

Hi!
Thanks all for your quick response. I have a 20 gallon tank, wishing it was bigger, and the filters i'm using are Aqueon (thats the new one) and Aqua-tech.
I was just looking at the goldfish book I bought yesterday and wondering how many fish I should put in. I've been getting conflicting answers to this question.
I love fantail goldfish, and koi, but am feeling obligated to get 3 comets and name them George, Georgina, and Georgette, Comets are what started this whole thing, they were given to me by a friend's 7 yr. old.
I'm only going to start with one fish at a time so as not to overload the whole system, and I know the fish are going to grow and would like to upgrade my tank when the husband allows, maybe in a year or so when the house is finished and I have a place to put them.
Any suggestions?

 

Hi Luvliijo and welcome to 3 reef

rule of thumb in coldwater aquariums is 1 inch of fish for every 2 gallons of water
thus you could have a maximum of 10 inches of fish ( dont include tail )

of the fish listed above
Koi grow big and do it quickly IME , Comets like a lot of space

Fantails would be the best of the 3 to keep in that sized tank IME
and 3 small Fantails introduced 1 every other week, after the Ammonia and Nitrites have zero's would be your best option in a 20 gallon tank

Steve