flourescent tubes

[Cavafish]

Hi

I need to replace my tubes and would like some further information on the type I should get.

The ones I have at the moment are standard Phillips tubes marked up as TLD 36W/29 and TLD 36W/54 that came with my Juwel tank. Do I need to get replacements from my LFS (or the internet) at £12-20 a go or can I get tubes from the local hardware store?

I know that the 36W refers to the wattage of the bulb but what does the TLD and the 29 or 54 refer to - is it colour?

Also I have seen in other threads that people are refering to 3600K and 10,000K - what does this mean??


Boy, I do ask a lot of questions

Can anyone give me any enlightenment on this?

Cheers

Cava

 

[Lateral Line]

Yes, you can basically assume the TL-D 36W/29 has a colour temperature of 2900K and the TL-D 36W/54 has a colour temperature of 5400K

One of the common units used to indicate the overall colour of a lamp is a "black body radiation" equivalent temperature. It is roughly the colour a black body would appear heated to the temperature.

As you warm up a bit of metal for example, it starts to get red, as it gets hotter, yellow, hotter still white, eventually through blue into the ultra violet.

A 2900K lamp is redder then normal daylight, a 5400K much more natural.

What to get depends on what you want to do with the tank. For normal freshwater tanks, avoid overly "hot" lamps, they stimulate algae. For planted tanks, the ideal range is something between 5000K and 6700K.

There are other measures of colour rendering, CRI is Colour Rendition Index, where 100 is perfect. Lamps over 80 are okay, higher is better. The TL-D series lamps are not the best in terms of CRI, (their spectrum is very peaky rather then "full spectrum"), but if you have no trouble with them, no worries.

You do not need to get lamps from the LFS, however, you may not be able to get lamps of suitable spectrum elsewhere, mail order is always a possibility. Make sure you replace the lamps with a lamp of the same type, i.e. a 36W T8 should be replaced with a 36W T8, the starter is designed to fire specific lamps types and may not work safely, or at all if over/under driven.

 

[Cavafish]

That is a brilliant bit of information Lateral, many thanks

As you so obviously know your stuff on this can I pick your brains some more??

Just another question then; how do i know if I have T5 or T8 lamps at the moment? What does T5 & T8 mean?

It would appear from what you are saying that the tubes I have are ok in terms of 'hotness' and I do get some algae but my bristlenose plecs just love that . I do have a horrible brown algae growing on my bogwood (one piece inparticular), whch has now developed into a tufty sort of growth. Could this be attributed to the failing tubes (as it only appeared in the last few months) and is there a 'temperature'/'colour' tube I should be looking at to control/eliminate this?

I think I am just going to go to my LFS to buy my tubes rather than shop around so is there a better brand than another or any other way of telling a 'good' tube from a 'poor' one? I am more concerned about wasting money on poor quality rather than spending more on good quality.

Cheers

Cava

 

[Lateral Line]

T5 and T8 refer to the diameter of the lamp. It is a somewhat "quaint" measurement, it refers to the number of 1/8 of an inch the lamp is in diameter. A T5 is 5/8" in diameter, a T8, 8/8 or 1" a T12 1½".

Increasingly, you will also see things like T26 quoted, which translates to 26mm in diameter.

Brown algae is normally caused by diatoms, not algae and is often a sign of low light. Are your existing lamps old? Fluorescent lamps fade over time, how quickly and by how much depends on the build quality of the end electrodes, which tends to be a function of the price - a cheap lamp will fade faster and deeper then a good quality lamp.

What to get tends to be difficult. I don't know what you have available. Hagen xxxGlo lamps are fairly generally available, the 6700K LifeGlo and/or 4200K SunGlo might suit. Interpet Triton lamps are also reasonably common, in fact, I still use them in combination with other lamps.

That said, if you have had good experience with your Philips lamps and can get them, why not? They will probably be cheaper.

 

[Cavafish]

Manythanks again Lateral. I am off to the shops now to get some.

Interesting what you have said about the brown 'algae'. I has only developed in the last 4-5 months and the bulbs are 16-17 months oldwhich would indicate that they should have been changed at a year (as per the instructions ) instead of left.

I generally let my LFS influence my decision making as they are really good folk so my final selection may be down to them but I always try to arm myself with all the information first so as I am not blindly led. This is how I know I can rely on their advice - it matches the good stuff I get from here.

Thanks again,

Cava

 

[Cavafish]

Just got an AquaGlo (18000K) and a Life-Glo2 (6700K).

Looks good but had to put the Life-Glo at the front cos it made the fish all look a bit red otherwise.

many many thanks for your help


Cava