It's Starphire Glass, not sapphire glass. Sapphire glass is used for making watches.
If you are considering nano tanks, what is the rational for using Starphire glass?
Given the fact that your light source is not strong and the water may be tinted from the wood, it defeats the purpose. There is no advantage from using color corrected glass such as starphire glass in such small setups.
Cheers,
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