Sylvania T8 Activa 172

[Tom Gunner]

I was having a chat with my local light supplier about the Philips TLD96 (6500k) bulbs for a planted tank, and he suggested I go for the Sylvania T8 Activa 172 6500K (36 watt) bulb, as this rates 98 on the CRI (color rendering index) - which I believe is the highest quality light you can get out of a tube.

Has anyone used this tube?

I'm planning to fit 5 tubes (180watt) on a 1200X45X45 tank. Has anyone else got a setup similiar to this?

Cheers.

[SpidersWeb]

Yep. I've got 5 x 4ft tubes on my 1200x400x450. I used tinfoil as a reflector but would probably recommend just using white paint.

Nice and bright but I'm using the TLD86 6500K T8 tubes they're a nice bright white, no visible problems, but I've had hair algae problems which are probably unrelated but will be keen to hear what others say about the importance of the CRI with regards to plant/algae growth.

Next time I'll use higher quality T5 tubes and/or MH.

[Tom Gunner]

I'd be interested in finding out more about T5 lighting - I've only used T8's and I'd like to find out the benefits in using 4ft T5's over 4ft T8's. Are they simply more powerful a light?

SpidersWeb - with your 5X36watt setup - are you finding that amount of light'is sufficient for that size of tank? Do you have any problems with specific plants?

I'm doing some research into CRI ratings and planted tanks - I'll post my findings as soon as I know more.

[richms]

I was having a chat with my local light supplier about the Philips TLD96 (6500k) bulbs for a planted tank, and he suggested I go for the Sylvania T8 Activa 172 6500K (36 watt) bulb, as this rates 98 on the CRI (color rendering index) - which I believe is the highest quality light you can get out of a tube.

Has anyone used this tube?

I'm planning to fit 5 tubes (180watt) on a 1200X45X45 tank. Has anyone else got a setup similar to this?

Cheers.

Check the brightness of them, the last time this came up some figures were posted so perhaps see if you can search them out (for the 965 philips tubes) and see what the output of these other tubes compares. It was quite a bit lower then 865 tubes when compared. I sure didn't find them bright enough to light my garage when I got a couple, they cost a hell of a lot more and I couldn't see any difference in how things looked.

[Tom Gunner]

richms -

I've been doing ome research into the CRI levels of different bulbs and their suitability. An interesting read is this article:

http://www.aquabotanic.com/lightcompare.htm

From glancing through it I think the point you made about the brightness relates to the efficiency of high CRI (90+) tubes. I believe that because they cover quite a high spectrum of light, the appearence to our eyes is dimmer than a low CRI bulb, but I think the most important aspect is the spectrum peaks - this article is quite good:

http://www.aquaticplantcentral.com/foru ... arium.html

The main point would be to see which peaks are being utilised by the buld, the most important being:

Chlorophyll-a: 430nm/662nm

Chlorophyll-b: 453nm/642nm

Carotenoids: 449nm/475nm

So, I assume that if you try and match the bulbs to cover this spectrum, you would have all your plants light needs covered.

p.s. Reading back what I've written, it sounds like I'm some cocky expert on the matter - I'm certainly not, please chip in with contradictions. I've just read a lot this due to an exceptionally boring week at work.

I'd love to hear peoples opinions on this.

[richms]

Yeah, thats the same justification they use on those LED based grow lights, just having the right peaks to grow plants without the wasted light like the son-t agros also make. Funnily enough at the prices the added efficiency means that no one really buys them. cant really use on an aquarium because they look so damn ugly. I know that the reason I want the tank lit is so that it looks nice, and thr brightness from the 865 was way more pleasing to look at then the higher CRI of the 965's, which were too weak to even light my workspace. I couldn't really see things looking better under them either, but it may be different for someone looking at paint charts or fabric which is what they advertise them as being good for