Which T5?

Majsa

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Partly triggered by the T8 thread, I think I it's time to replace the T5's of my 2-year old Proxima 175 (70x50 cm). Not being able to decide about LEDs I thought I'd just go with the same original Eheim Daylight T5's (x2) but...they are discontinued. There are so many options out there but can't find any with the same specs. They are 549 mm, 24W, 6500 K, 1850 lumens each. Any suggestions? How important is it to have the same Kelvins and Lumens? If I go for 6000 K and 1800 lumens, can I expect the same result?
 

Edvet

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can I expect the same result?
Yup,
Colors are in the eye of the beholder only, in general plants don''t give a rats ass.
You can use any fitting T5's, H(igh) O(output) types give more bang for the buck, but more bang can create more disaster (read algae)
If you change lighting just pay close attention to the tank/plants, if you see trouble decrease lighting times a bit ( and or increase distance if possible).
 

PARAGUAY

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I use the Arcadia Plant Pro. For a more "Tropical" look I use with iquatics tropical tube with a slightly pinkish look. 6500k ,think the iquatics is in a similar k.Four over the 55g is too much and two tubes is usually enough for the plants I tand to use. All I bother about is how it is to view/ look at as Edvet says
 

Majsa

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Thanks all, I was thinking of the Dennerle Trocal Amazon Day + Special Plant but...

Why ?. Life time of T5 tubes to 80% brightness level is generally about 5 years.
now I think no hurry! I thought the drop in brightness would be much bigger than that.
 

dw1305

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Hi all,
now I think no hurry! I thought the drop in brightness would be much bigger than that.
Realistically you can tell when an electronically ballasted tri-phosphor T5 tube needs changing, and that is when it doesn't come on.

If it is a "soft start" ballast, and you are only turning the light on and off twice a day, the active life may extend to 40,000 hours, with very little lamp lumen depreciation. Philips are quoting 95% lumen maintenance after 35,000 hours for their <"T5 high output lighting">.

cheers Darrel
 

Simon Cole

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Thanks all, I was thinking of the Dennerle Trocal Amazon Day + Special Plant
Wow - That is one expensive bulb. My 10,000Ks (daylight) cost about £4.50 each, and they were 849mm high-output Osram bulbs (GEs cost a little bit more). Obviously a good pink bulb will cost you about £11.00, so it's a bit more. I know it matters getting a good bulb that you enjoy if it has a nice red-blue balance: I used to love some of the Trigon bulbs and they used to cost quite a bit. But for a daylight bulb, I cannot see any advantage. You made a great choice getting a Eheim Proxima 175. They use commercial fluorescent tube sizes, so you have an almost endless choice of suppliers. Other lighting manufacturers try to lock you into buying their bulbs which only come in their own bespoke sizes. Why don't you get a load of different bulbs for £10 or £15 and have a play around. Dependabletradingltd are on Ebay and will get bulbs to you on the next day for free. You don't need to worry much about the lumens, but you simply need to choose HO bulbs as they will all be roughly the same, but take Edvet's advise above. Below is a picture of one of my 4 tube set-ups: 1 Degenbao AquaRed, 2 Osram Daylight 10,000K, 1 Osram Extra Warm White 2,700K (all tubes high output).
WP_20190504_04_48_39_Pro[1].jpg
 
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Majsa

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Thanks Simon,

They use commercial fluorescent tube sizes, so you have an almost endless choice of suppliers.
That is a good point, I was only looking for aquarium lights so far but if I can choose any T5 that's great. For daylight bulbs there aren't really differences then (except for the price)? Could go for a nice coloured one and a cheap daylight bulb. But that will be later, since I decided to wait until the "old" bulbs fail :)
 

Simon Cole

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I would like to think that each of the aquarium lighting manufacturers has their own factory producing or specifying the exact spectrum required for aquatic plant growth. Although, it is far more likely that they simply re-brand existing tubes which are cut to order. If this was not the case, then by now I would have expected a far greater selection of tube colours favouring different aquarium styles. In fact, we basically see day, natural and tropical tubes that look fairly identical to daylight, warm white, and pink commercial tubes. There is certainly no difference in luminosity (light strength).

The key points are that Kelvin does not tell you the colour of the tube. You can have 10,000K tubes that range from magenta to aquamarine. The straight lines you see in the diagram below follow each kelvin rating. Secondly, plants do utilise a lot of green light. What we were taught in school about blue and red light being more important for photosynthesis was completely incorrect. Since the late 2000s there has been a lot of research indicating that green light is more effective due to its ability to penetrate the leaf, and presumably water depth, than red for instance - and there are continuing revelations showing how much better different groups of plants grow with high proportions of green light. Thirdly, we always see spectrographs produced by the manufacturers that show specific patterns of wavelengths. I do not believe there is a perfect graph for all aquatic plants. Moreover, I have never seen these tests (spectrum charts) externally verified. I suspect they are created as part of sales and marketing. One of these days I will get hold of a spectrometer and prove this, but the plants will not care - they'll grow just as well. So really, everybody should take this with a pinch of salt. Buy whatever tubes make you feel good Majsa :) - when your tubes eventually die.
cd0351b1dd2eb640b013216895ca6f694c24079c_large.jpg
 
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