Advice please re changing Substrate

[Clopsy]

Hi All,
I have a plan in mind about how I will about changing my substate to something more suitable for plants.
I am hoping some of you will be able to give me some feedback as to whether it will work or not... or any other steps I should consider. I am relatively new to all of this an had no idea what I was doing when I started.. hence trying to rectify things now. The plants I have are growing ok but could be much better I'm sure with the right substrate.

My current set up is as follows:
Tank: 350l Juwel Trigon
Substrate: between 1-4 cm of 2-3m Sand
Filter: JBL Cristalprofi 1500l
Pressurised C02 @ 2bps
Ferts: EasyCarbo & EasyLife
Lights: T5 2x24 and 2x45Watt

I now have a spare 80l tank that a friend has given me and my plan is to take all of the fish from my current tank and transfer them into the 80l for a few days while I work on removing the existing sand from my current tank and putting in Aquabasis plus and JBL Madano as new substrate. I will then transfer back the fish to my 350l. I will take out the existing plants and leave in a bucket of tank water while I am working and replant when the new substrate is in place.

My questions are..
Because I will be using water from an existing tank (cycled etc) will my fish survive ok in the 80l tank ?

Should I set this tank up with no fish and leave it run for a week or two like a new tank or can I just put the fish in straightaway ?

Once I have the Aqua Basis plus and Mandano in the new tank will I have to wait for a while before I put back the fish or will the water parameters (Amonia etc) be unstable while the new substrate etc settles.

Any ideas how much of the Auqabasis and Mandano I will need ? I'm pretty mathemactically challenged but by my estimation 10l of Aquabasis and 15l of the mandano should be sufficient ?

I don't really know the names of the plants I have so I've posted a pic below of my current set up.

I'd appreciate any feedback before I dive into this.. I haven't actually purchased anything yet so if there's another type of substrate I could/should use just let me know.

Thanks in advance..

 

[Fishperson]

Thats a nice looking tank you've got there! I don't think you would really need to change substrate if the plants are growing fine. But if you want to:

1. When you put the fish into the 80l tank put the old filter(s) on the 80l while the fish are in the 80l.

2. I don't know what aquabasis or madano are sorry.

3. What do you mean "set it up like its a new tank"? It's been cycled right? If so just put the filter on whatever tank the fish are in. No waiting needed.

4. Do a large water change after the new substrate has been put in and settled to get rid of excess nutrients or silt.

I still think it'd be a nuisance. Unless this is being converted to a high light tank, root tabs will be sufficient for most plants.

 

[Clopsy]

Alex, thanks for the reply.. I guess I want to be rid of the sand anyway.. I'm endlessly trying to keep it clean and I haven't nearly enough of it in the tank anyway.
Good idea re using my existing filter in the smaller tank.. hadn't tought of that.
Thanks again for the feedback