Difference between 430mm (17") wide tank to 530mm (21") tank

[Menashay]

Hi,
I am very new to marine fish tanks. My question relates to fish tank aquatic life & fish tank maintenance.
I have a space for a built-in fish tank 1,370mm (54") (L) x 430mm (17") (W) x 640mm (25") (H). This space is already built though I can make some changes.
These changes will require construction changes though not big.

I can extend the frame to give me a bit wider space from 430mm (17") to 530mm (21") [full dimensions of tank become 54" x 21" x 25" instead of 54" x 17" x 25"]
I wonder however if this additional width worth the effort.
Is there going to be much of a difference in terms of aquatic life and required maintenance between the two fish tanks?
Thank you for your tips and recommendations.

 

[Reefing102]

Though it’s only a few inches, I think you would find that few inches really helps with aquascaping. I’d definitely go as wide as possible. The only issue you may run into, possibly, is light coverage. Also if this is built into the wall, depending on how this is set up, that few extra inches could make difference for maintenance, so wider may not necessarily be better. As for livestock, ultimately I don’t think you’d have too much of an issue

 

[griss]

Personally, I’d go with the 21mm if you can. But that’s personal preference from an aesthetic standpoint.

 

[kfisc]

Agreed- the more space the better. It's a surprise at times how you wish you had a little bit of extra space when reaching or placing things.