gf225

I currently have 4 x T8 18W 6500K ( CRI 98 ) in my 33G. I'm fairly happy with the results, aesthetically and practically.

However I'm tempted to swap two of the 6500Ks for 10000K. What do you think the overall effect would be on colour rendition - would my Cardinal tetras appear less red, more blue? Or does it depend on the CRI of the tubes?

AaronT

In my experiences mixing 6500k and 10000K half and half gives a very pleasing coloration to both fish and plants. I say give it a try.

Simpte 27

I agree. 6500-6700K and 10000K is a nice mix.

gf225

Thanks. I did hear from a few sources that this mix was ideal.

So the reds will be fine?

Now I just need to find a cheap UK source of high CRI T8 10000K tubes.

For any other UK people out there these are great T8 6500Ks and very cheap too - http://www.thearc.co.uk/catalogue1.p..._group1=Activa

And they do cheap HO T5 - http://www.thearc.co.uk/catalogue1.p...Daylight+6500k

Faruk Gençöz

As for the T8 10000K I would suggest Phillips Aquarelle.

Left C

Here' another T8 combination that looks and works well IMO. It's Zoo Med's Flora Sun and Interpet's Triton (called Tri Plus now).

gf225

Thanks. I've heard that's quite a pink light compared with other 10000K tubes that are more blue. Is this true?