Want To Change My Tubes

[SuperColey1]

Hehe ok I get that part. So what is the 8000k all about on my tube?
And also, if I can only get 30w out of it, is there any point in changing it, since it won't get brighter anyway?

8000k is the Kelvin rating which means the colour it appears to your eyes. 8000K will probably give the tank a quite green appearance.

A 4000K would give the tank a pinkish appearance, 2000K quite a yellow appearance.

K (kelvin) is the colour temperature.

Whether you should change your tubes is up to you really. When the tube is brand new it will be much brighter than when it is 2 years old. It will deteriorate over time and the longer you leave them the more deterioration. Therefore although it will still be consuming 30W of power it will not be outputting the potential light that 30W could give after the bulb has started to be used.

To see what I mean buy a new tube of the same K rating and compare them. If yours is still bright then you can put the one you just bought in the store cupboard ready for when you need it.

AC

 

[Rooster]

Hehe ok I get that part. So what is the 8000k all about on my tube?

And also, if I can only get 30w out of it, is there any point in changing it, since it won't get brighter anyway?

The 8000k bit is colour temperature.... or plain old COLOUR in English ! LOL The higher the number the bluer the light... lower numbers give a redder light - its to do with the "electromagnetic spectrum" - chicken jumping yet ? LOL

The Sun has a "temp" of 5780k , so a lamp of that rating would "LOOK" the same as sunlight... making a bit more sense now ?

As for "PAR" and what not, think of it this way.... your kettle USES 2000 Watts or so, but doesnt give out any "light".... a street light may also USE 2000 Watts of electricity,
and it gives out loads of light.... its the word "light" thats the problem, our eyes can only see part of this spectrum mentioned above, and have evolved to work in sunlight, so lights of some colours look "dimmer" than others, we are really bad at seeing red.... traffic lights use lamps that are LOADS brighter in the RED than the green, so as to "look" the same brightness to our eye.

Therefore, choosing a lamp of the "right" colour will "look" brighter to your eyes... this is also compounded by the fact that technology has improved, and you now get "more light" for yer Watt !
So YES a new 30W lamp CAN be brighter than the 30W one you have now.... apart from the fact that they get dimmer with age (dont we all !)

Ramble over.....

 

[Truck]

apart from the fact that they get dimmer with age (dont we all !)

LMAO

 

[waterdrop]

how many hardware forums does it take to change a light bulb?

oh, gotta love it! What a thread! A gem of a post there rooster.. not joking, really enjoyed it and also the good info (as usual!) from AC!

 

[Dave Spencer]

The Sun has a "temp" of 5780k , so a lamp of that rating would "LOOK" the same as sunlight... making a bit more sense now ?

And this varies with clarity of water, depth of water, aspect of the sun, shade and so on......which is why most of the planted community go for CRI. Just choose the light you like the look of the most.

Dave.

 

[OldMan47]

I do spend time looking at the CRI on a bulb I am considering. That is the color rendering index and relates to how well the color of things under the light look the same as the item would look under sunlight. A CRI of 100 would be a perfect reflection of the "real world" color.

Edit: A CRI of 80 means the bulb does a terrible job of reflecting the real world.

 

[MermaidMel]

how many hardware forums does it take to change a light bulb?

LOL!! I do feel very 'dim' but if people can answer, then I will ask! I am learning and getting this more and more as we go. Yes my tank lights are somewhat greenish, if I was to go for 6 or 7k I would probably more of a white then? That sounds better to me, think I'd prefer it. The tank is not even a year old but I think its gotten dimmer and also because its probably a cheap tube, since its a cheap make of tank. The depth of the water is about 2ft so quite deep. Also have a dark rock structured background rather than something reflective, might not help but I like it. Lots of dark wood and dark slate in the tank. The only thing that catches the light is the fish, the central anubias and the yellow sand. Quite contrasting and natural looking though. I may have a look at trying a new tube with less K [oh get me haha] and see how it compares. Good work people, you've successfully educated and very stupid mermaid.

 

[SuperColey1]

Old man. Make sure you don't buy any cheapo 7 CRIs then

Its very hard to get a natural white with 1 tube. There is a very fine line in the K rating between the light looking pink (4000-5000K) and the light looking green (6000-8000K) therefore if you are limited to 1 bulb then I would aim for 5500K. However to be sure you get what you want from the light it needs to be a 955!!! otherwise you may buy a 5500K and because of its inaccuracy of the colour rendition then it may appear either side of white!!!!

This is why most hoods these days use 2 tubes. Then the colour can be balanced out.

Here is a simple example:

This is a 4500K light and at first glance without looking at the next pictures it may look good to you. That is because this is a top quality light (945)!!! It is actually a pink light and you will be able to tell once you see the next 2 shots.

Again a top quality light (965) This is a 6500K and you can see the greeny tinge it gives out.

This is how it looks with the 2 running together. Not pink, not green but pretty natural I think you'll admit. Its the combination of the 2 lights that achieve this look.

You can get this natural colouration with 1 tube as it is such a fine line between pink and green. Even when you buy in this corridor and the tube is top quality it could very slightly veer one way or the other!!! Over time of course it will also give the appearance of getting dimmer and this can also change the appearance of the colour it gives out.

You did ask about lighting and tubes. lol.

It is a very tricky subject.

I see you talk of a cheap tube because its a cheap tank!!! I would bet an identical replacement to the one you have would be more expensive than buying a far superior light that wasn't branded aquarium!!! For example something like this is pretty good quality:

http/www.lampspecs.co.uk/Light-Bulbs-Tub...x-Osram-15-Watt

AC

 

[MermaidMel]

OMG. I need a lie down after reading this thread back!!!