Is this right?

[Stege_saurus]

So this weekend im planning on pulling all the fish out of my DT to get rid of Ich over the next couple months. I've noticed my system has Ich, don't know where it came from because I quarantine all new arrivals with prophylactic treatment, I want to get rid of it all together.
My plan: im going to buy a 40g long aquarium and use a 20g aquarium I have on hand.
My issue: I have quite a few fish, which I will list at the bottom of this post. The issue that ensues is I only have 6ft of space to work with for quarantine tanks and I have a small budget unfortunately. My Sailfin Tang is currently the only one showing signs of Ich.
My question: Will this amount of fish and space be okay for the next 76+ days?
Stocking list(fish length):
1 Yellow Tang (3in)
1 Sailfin Tang (3in)
1 Tomini Tang (3.5in)
1 Blue Tang (2in) *Currently in QT
1 Snowflake Clown (1.5in)
1 Black Ocellaris Clown (1in)
1 Lemon Damsel (3in)
1 3-Stripe Damsel (1.5in)
1 Blue Damsel (2in)
1 Striped Blenny (3.5in)
1 Six line wrasse (1.5in)
1 Foxface Rabbitfish (2.5in)
1 Orange Spotted Sleeper Goby (2.5in)
1 Arc eye Hawkfish (1.25in)
1 Scooter Blenny (1.5in) *Currently in QT
1 Neon Dottyback (3in)
1 Splendid Dottyback (2in)

Any advice is appreciated!

 

[Idoc]

Wow, that's a lot of fish for a 40g tank... even with a 20g added to it. That's going to be some tight quarters... tempers will probably flare up.

 

[Stege_saurus]

Wow, that's a lot of fish for a 40g tank... even with a 20g added to it. That's going to be some tight quarters... tempers will probably flare up.

Fortunately all the Tangs have known each other for some time and get along well. I was planning on putting the Tangs and a few others in the 40 and the smaller fish in the 20...
Or should I just work on Ich management because that may be too small? Ugh...

 

[The Aquatic Arsenal]

Why not just treat the Sailfin Tang? The stress alone of catching all of those fish will be stressful on the fish, making them more vulnerable to getting ich as well.

 

[Stege_saurus]

Why not just treat the Sailfin Tang? The stress alone of catching all of those fish will be stressful on the fish, making them more vulnerable to getting ich as well.

I thought about doing that, would it be more beneficial to the system?

 

[Idoc]

I thought about doing that, would it be more beneficial to the system?

If it were me, I think I would give that a try first. Then if others present with ich, then step back and re-assess maybe. I couldn't imagine trying to catch all those fish.