Help please! Question about filling my reef with water to fill the gap at the top!

[Scape]

Hello everyone,

I have a reef aquarium and I was wondering if anyone would kindly help me with a question I have, Any answers will be highly appreciated,

So I have about a 2 inch gap between my water and the top of the tank, I now want to fill the tank up with water about half an inch to fill this gap, when I initially setup the tank I left too much space for displacement and didn't put as much water in as I wanted so ended up with this 1 inch or so gap,

The question is do I fill this gap with freshwater like a top off or do I mix some salt water and then put that in to fill the gap?

All my levels are currently tip top (good) I just want to fill the gap!..... Help me fill this gap!.. Please.

I apologise if I'm not being clear or maybe have confused you and I appreciate your patience in my question.



Thank you

A.A

 

[Homelander]

Welcome to R2R!

You'll want to fill up with saltwater. If you fill it up with freshwater it may drop your salinity.

 

[Scape]

Wow thank you so much!

That's really helped me a lot and I really appreciate you taking the time to answer my question!

Very helpful answer and so quick!

Have a great day!

A.A