It's maybe because the hobby is quite young in the UK compared to the US. 3-4 years ago everyone was putting more and more light over their tanks because of the common myth of 'high light' and 'low light' plants etc.
Problem is that I don't believe in high light and low light plants. I think there are high nutrient/CO2 plants which people tend to increase with the light and therefore assume it is light that determines the plants you can go.
A 'reasonable' amount of light is obviously needed to get some plants to grow in a form that is desired for example HC staying low and carpeting but not silly amounts. I used to read posts of people who were 'boasting' of their new 6WPG setups which made me laugh. I think 3WPG these days is very high light and will do whatever you require from the plants.
The idea of not needing so much light is however starting to filter through. The UK is going this way more quickler due to us still 'learning' and 'exploring' whereas the US being much more established is taking it's time to understand that their beliefs were wrong.
Same as happened with nutrients. It took ages for people to understand that the radical 'theory' of excess nutrients (namely phosphates) were not to blame for algae because it had been the belief for so long.
Newbies will waste money for a long time yet while so many advise 3WPG as 'needed' and of course retailers are always way behind the 'current thinking'. For any combination of the following:
1 - They have been in the hobby so long that they cannot believe their long known beliefs to be wrong
2 - They aren't plant people and so go by beliefs they heard years ago
3 - More light costs more money which means higher turnover
4 - They have stock to sell
I only started in November 2006 (Not long ago) and even then nobody scaped with 1WPG of anything really. Every tank with this amount of light was using only the supposed 'low light' plants and feeling really limited on choice. I had a go though as did George Farmer and a few others plus Tom Barr was also confirming our thoughts that not so much light was needed and it worked. We did use low light (1WPG) but we injected pressurised CO2 and dosed as per EI or similar regime.
That was it really. From there on it was obvious that the >4WPG setups that we had been seeing were pointles wastes of money. Quantity of light wasn't really an issue. It was more quality and distribution much as it is with CO2 and nutrient. Much better to have 1WPG of light spread over the tank than 3WPG in a small space not spreading so well (CF)
Therefore people can save their money and spend it on something that is needed. I have been in the hobby as I said for 26 months!
I started with 1WPG T8 and upgrades have been:
Jan 07 - new tubes, reflectors : £35 (1WPG)
Mar 07 - upgrade to PC 55W + 18W T8 : £60 (2.5WPG)
Sept 07 - 'downgrade' to T5HO : £60 (1.8WPG)
I currently use just 1 of the T5HO so thats 0.9WPG. less wattage than I started with although it is T5HO. I could've basically stuck with what I started with and saved myself £120. lol
But these were the days when I was being advised rather than advising and like many I believed what I read and was told. Once I started to understand planted tanks and how they work I started 'testing' and experimenting for myself rather than being led.
Saying that I will be using high powered LEDs very soon which I am currently DIYing. These are superbright but will use less wattage, give a sun movement effect.
This is what I mean by using a quality spread of light rather than powerful 1 piece units:
This is 1 light. No matter what the power it will be brightest directly under the tube and darker at the sides:
The more lights you have the more their rays overlap and 'fill in ' the dark areas:
Compare the next two pics:
2 x T5 PC tubes versus 4 x T5 Linear. Same wattages but Linear can be spread better. You can see what I mean about light spread here:
The PC is obviously blasting light in areas and leaving others darker. With the Linear there is much less difference of light intensity across the tank
AC
