According to this months Practical Fishkeeping for May, they are and Gabor Horvath has done a Gear group test on all manner of LED lighting mentions the Superfish series come out well ,any initial costs offset by the thousands of hours of useage, compared to replacing the standard bulb every 12,18 months
I guess if you need to replace your bulbs anyway LED tubes are a good option. But the bottom line for me would be whether I found the colour rendition better than the fluorescent tubes, and whether I needed the higher output.
Most T8 LED replacements tends to be slightly less lumens and will generally not be suitable for straight T8 fluorescent replacement as most T8 ballasts/controllers for the last 15 odd years have been electronic control. Do have the advantage of maybe 2/3 power consumption.
It highly depends on the used LED inside.. There are still quite some replacements out there holding an older generation LED such as the SMD 5050 with a much lower output than newer generation SMD strips that do outperform simmular lenght T8 output. Thus it is hard to say without having the complete specs from the replacement tubes and which led type it holds internaly..
Another point of consern is do you take replacement plug and play tubes, they are designed to still run off the tubelight balast. Or take the Retrofit tubes, that don't require the balast but a direct wiring setup, can be placed in the excisting TL tube fittings/hood.
In any case, the LED tube internaly holds a SMD strip 12 volt or 24 volt. It contains a little driver/transformer converting AC to DC to run on the ballast or directly on the mains. The money is not in the SMD LED strip that is your actual light source nor is it in the driver. The money is in the design of the replacement casing and the plug and play convinience.
Are they worth the money?.. Tricky question.. Oftenly if you resource the specifications of the used LED type you might find that the actual used light source (The strip) only costs a fraction of the so called replacement holding it. Even if it outperforms a simmular T8. Bottom line saying if you buy the strip only find a proper way to case them and drive them from a proper powersuply than you can make it even cheaper. And be able to upgrade it on the fly with placing only beter performing newer generation strips in the excisting casing.
Than it comes back down to plug and play convenience. That is a personal desicion to make. Are you less of a diyer and don't want to hurt your brain about thinking how to fix it.. Than simple plug and play can be worth the money aside from performance.
Performance wise, buying complete factury setups is always a gamble in how truthfully does it compare to the previous T8. Since a manufacturer thinks in the future, designs a concept with the todays standard to create a steady performing product. And 10.000 pieces role of the assembly line and are shipped out to shops. Mean while LED industry keeps on developing rather fast. The first 1000 of these setups are yet not sold and newer beter LED strips are available again. The other 9000 still in the shops are yet to be solled and already outdated by far. Seeing it from that perspective.. Worth the money?.. I would say not quite if it doesn't meet expectation in performance. You pay for a design and the convenience it gives you with an outdated source and also outdated price that can be bought for sale with a huge discount else where because its obsolete.
I was thinking of replacing the tubes directly as the tank/hood/etc is custom and getting the old cables out without cutting them, and getting new ones in could mean drainng the tank.
Now you come to mention it I have a spare 1.8m of IP20 7.2W/m RGBW strip, and some Al profile (with defuser) to fit it in. (Its left over from something entirely un-aquatic, so I'd need to source a controller & PSU.) If my maths is correct, that equates to approx total of 800 lunens, so is that likely to be a viable alternative to a pair of 900mm T8s?
The LED tubes would cost me 5.7 times as much money to buy as a T5 fluorescent. I'm going to ignore T8s in my discussion below because they put out far less light.
In terms of efficiency, it all depends upon whether pulse width modulation is present. I would be surprised if LED drivers are included within many of these new replacement tubes. So although you might get the same or even more luminosity, it is modulated over time.
Personally I have never noticed that florescent tubes need to be regularly replaced, and I can recall one discussion on this forum that indicated their loss in terms of efficiency is exaggerated, particularly on an 8 hour cycle. They do degrade over about three years, but looking at the maths, I can find no reason to justify LED replacements.
In terms of energy consumption, I suspect that the lower wattage assumptions are very much a factor of modulated current. After all, it is something quite tolerable to the human eye. Running LEDs at their correct unmodulated voltage would actually require a heat-sink, and would draw a higher wattage, and in my opinion this would shorten their lifespan considerably. So I believe that much of the published evidence supporting one technology over the other is unreliable. I believe that plants benefit from unmodulated light output.
In terms of light quality and visual appearance I find that both have their benefits. But noticing this difference could be hinting at an unmodulated set-up in the first place.