Can it be done?

[littlefoxx]

Because red sea calculated with inner dimensions and water height factored in, yes, the water volume is only 192 for display 48 for sump. But, to put into perspective if calculated the same way on your tank, your display water volume would be between 240-250 (if your 300 is 8’ by 2’ by 30”). I get your point on why water volume matters though

Yes exactly, I know all I have around 250 gallons of actual swimming room I also currently have 10 fish lol

 

[fishguy777]

Can we see pictures of this tank/ fish that are already there?

I just added 3 in, two in acclimation box.

Now the display holds:
Blue dot ray
Hi fin snapper
Naso tang
Achilles tang
Atlantic blue tang
Blue throat trigger
Polleni grouper
Flame angel
Hippo tang

 

[Cheese Griller]

I just added 3 in, two in acclimation box.

Now the display holds:
Blue dot ray
Hi fin snapper
Naso tang
Achilles tang
Atlantic blue tang
Blue throat trigger
Polleni grouper
Flame angel
Hippo tang

a 7' tank is inviting disaster with the Achilles and Atlantic blue. Both can become extremely aggressive, aside from the fact that both of them honestly need an 8' tank IMO. I can't speak for Achilles, but I observe Atlantic blues in the wild on a regular basis and they are HUGE. Easily 12" and probably 3-4" thick.

You've been posting a lot of threads on here and most of the advice seems to be falling on deaf ears- I would sincerely recommend heeding the advice you've received- that your tank is already at the maximum stocking.