Ok, So Here Is My Plan To Transfer My Fish To A New Aquarium...

[clovis]

....let me know where I am going horribly wrong.
 
But first, a big kudos to this webforum with so much advice being given that seem invaluable.  Bravo to all the participants.
 
So like all newbies, I have done the get-a-goldfish-for-my-son-in-a-bowl (the goldfish not my son).  Realize my mistake, and got a 10 gallon tank (second mistake).  Realize that if you're in for a penny, you're in for a pound and now just got a 20 gallon long.
 
Now here is the tricky part (I mean other than the fact that I am mostly clueless).  The tank I just bought was second hand from a couple who up until a few days ago had fish in the tank.  They cleaned the tank (no soap products obviously) but left the dirt and gravel at the bottom in a few inches of water.  There is duckweed and some snails in the water.  So I figure it's a mostly cycled tank (took readings today and No3 was a tad high.
 
So that is a the set up. This is what I am doing.  Tell me where my plan is risible:
1)Put in about 8 gallons water in the 20 long
2) Take filter from 10 long put it in 20 long
3) Put filter of 20 long (that had been scrubbed pretty much clean by ex owners) into 10 long
4) wait a bit (how long I do not know) This btw is where I am at rigth now
5) move short plants from 10 gallon to 20 gallon
6) syphon out water from 10 gallon tank to bucket
7) move fish (5 tetra neons) from tank to holding bowl
8) tweak my back lifting up 10 gallon mostly empty tank off table
9) break my back pushing 20 gallon tank into its new spot
10) put water from bucket in 20 gallon
11) put fish in 20 gallon.
 
Let me know what part of this plan is absolutely ludicrous, and what might just be crazy enough to work.
 
As a bonus question, the 20 gallon long seems to have an ungainly amount of dirt and gravel in my opinion (about 1 inch dirt, and & and a half to 2 inches of gravel)  Is it a good or very bad idea to scoop some of that gravel up now?  Or do I just live with it?  ie is full of the good organisms that we are looking for in a new tank?
 
Well, looking forward to your answers.
Sincerely,
Clovis from France
 

 

[Ninjouzata]

I would just put the filter media from your 10 into the 20 long's filter, if there is room. It'd help to have the 20 gallon mostly empty before you move it, otherwise you could risk it cracking.
The substrate does hold a good bit of bacteria so you may not want to mess with it right now. 3" of substrate isn't bad, especially if you're going to have live plants.
 
Do you still have that goldfish or do you have just neon tetras now?

 

[elmo666]

Personally I wouldn't use anything in the new tank until it's been thoroughly cleaned, you've no idea what's in there, good or bad. Depending on how long all that dirt has been there since the tank was emptied it good range from bad to VERY bad. The nitrifying bacteria require a good amount of oxygen within the water to survive. Without it they die and will foul your water badly. You've also mentioned snails which soon get out of hand if you don't keep them in check.
I believe you would be best starting this new tank from scratch. If you have a mature, cycled filter on your 10 gallon, it is dealing with the bio load you now have. If you are simply moving these fish to the 20 gallon and not adding anymore right now it will be absolutely fine.
Empty the new tank, sterilize it by wiping over the tank with alcohol once thoroughly cleaned, then rinse clean. Clean the gravel if you're sure you want to use it, but I'd be buying new to top up what you have. Now, arm yourself with a few buckets. It would be great if you could warm and dechlorinate 10 gallons of new water, place a heater in the bucket if possible. Two 5 gallon buckets would be ideal. Then its simply a case of draining the 10 gallon into buckets, putting your heater and fish in one. Strip down the 10 gallon, you have around 2 hours play time, if your filter is external canister. If an internal filter keep it in one of the buckets with the 10 gallon water. now its just a case of moving the 10, putting the empty 20 in place, add substrate, set up filter, add some 10 water and freshwater, turn on and check. once the temperature matches that of the fish bucket, add the fish and then the rest of the water.
Leave the lights off for 6 hours to allow your fish to settle down.......... Have fun

 

[clovis]

Hi Ninjouzata and Elmo,
Thanks for the advice.
Of course I prefer Ninjou's advice as it requires a lot less work on my part (pretty much in line with my game plan), so before I go do something to really annoy my wife (mess up the living room) that seems quite labour intensive, do most people fall on the 'use the stuff that is already in the tank probably full of good bacteria' or the 'better safe than sorry.  Empty everything out and start anew' side of the debate?
Thanks
 
The tank I am guessing had been emptied 3 to 4 days before I picked it up, top had about 1 inch of water.  Had up until that time had a few fish in the tank.

 

[elmo666]

Ok, of course opinions vary, I tend to adopt the "put in the effort now to stop upset later" approach. Trust me, don't be in too much of a rush, take time to plan out what you want, time spent setting things up correctly is never wasted.
Now, as for that sludge in the bottom of the new tank. I'm afraid any useful bacteria is probably long dead and if you add water and fish to that you're gonna have all kinds of problems, the first being extremely stressed fish.
As said, that's only my opinion. But please, if nothing else empty the 20 gallon, wipe it down and rinse it and give that substrate a good rinse to, until the water runs clear.

 

[Gruntle]

I think I fall sort of between the two options. If there is any good bacteria in the substrate, a good rinse shouldn't affect them badly (use dechlorinated water rather than straight from the tap and you'll be fine). If any bad stuff (decaying plant matter, fish waste etc) is in the substrate, a good rinse will only help matters.
 
Your 10G filter has enough bacteria to cope with your bioload. so if you can use the filter media (pads, ceramic rings etc) in your new tank's filter you should be fine. If you have any issues, double the amount of water in your bigger tank gives you some time to correct things, more so than in the 10G. Bacteria repopulate fairly quickly (within a day or so), so since I can assume you have a decent sized starting colony in your existing tank there shouldn't be any issues.
 
If it were me, I would:
 
Put both filters into the 10G temporarily.
Clean the 20G including rinsing the gravel. Personally I'm not a huge fan of dirt, but that's entirely your choice, my plants appear happy to grow in gravel.
Empty the water from the 10G into a bucket and move the fish and plants into the bucket (which should give you a couple of hours before you have any issues)
Move the tanks, which both should be as empty as possible.
Once the 20G is in place, put the gravel in (top up if you wish), put your plants in, and fill the tank. You can use warm water to get the temperature where you like it. Dechlorinate.
Hook up the 20G's filter which should have as much of the 10G's media in as you can fit.
Put your fish in.
Monitor the water conditions for a few days.

 

[clovis]

Okeedokee.
Will do it your guys way.
Will take out all Gravel And give it a good clean.
Should I just toss out the soil at the bottom? (I'm guessing the answer is yes). And if
I do so should I replace it? I am planning on planting live plants.
Is it really just a matter of preference or is one option better than the other?
Thank you for walking me through this, it is much appreciated.

 

[elmo666]

As far as live plants go, a nutrient rich, slow release substrate is of great benefit. Tetra complete is a good example. Its designed to go below a top layer of gravel or similar, the root growth and plant health is greatly improved. The only thing you need to do is ensure you don't disturb and only gravel vac very lightly.

 

[clovis]

Hi all,
Firstly, Elmo, thank you so much for insisting that I start anew

I thought the tank looked just fine the way it was with all the old gravel and soil, but once I emptied it all out, cleaned it thoroughly, wiped it down, and filled it with fresh soil and gravel, the tank now looks positively shiny.
Having gotten rid of all potential good bacteria, I have decided to cycle the tank fully, since with the holidays coming up and our absence for 8 days, I have decided that there is no point in transfering the fish, and getting new fish in a hurry and then not being around should there be any troubles.  No need to rush things (other than an impatient 7 year old, and a probably even more impatient 45 year old).  
So now that I have all this time ahead of me, should I be looking into a new filter.  The tank came with an old  Aquarline Resun Magi- 380 filter.  Seems to me that it might be just slighlty underpowered, but I am not sure.  Any thoughts?
 
PS Elmo, nice to see that you are an artisan like myself.  I am a decorative painter.  Have taught some classes in England to some colllege decorative painters.