lighting position and tube

[gregorsamsa]

hi,

the 2 ft fluro light casing has a 15 watt tube that is about 460mm. I have not tried a 55watt or 2 x 36 watt PL fixture yet.

My question is, how are you able to ensure the plants at the two extreme end get sufficient light? I have tried mounting it (a 2x15 FL set) on a stand and this creates the new problem of the stemmed plants slanting towards the center. i foresee the same problem for a 55 or 72 watt fixture as plant head for the point source.

any solution (the 20 watt NA tube?)

jiesheng

[adrodema]

It might be a slightly smaller problem if the lighting fixture consists of two bulbs/tubes and not only one. Because the ends of each tube can cover each side respectively.

[Simon]

I don't think PL can cover the entire tank, unlike FL. The PL is shorter than our 2ft, so both ends will not be properly lit.

[gregorsamsa]

so is there a recommended solution other than the 20watt tube which is Japan made (thus other necessary fittings)?

i have seen the 18watt fixtures but i think after the burn in period, the end caps are also dim.

just now i also tried lifting the lights up and realised that it doesnt spread wide

problems problems problems.

jiesheng

[Barbarik]

2X15W FL is insufficient for most plants on a 2ft tank. A 55W T5-size PL (tube length is 2ft) is the least you should have. A 2X36W T5-size PL will give a lot of wonders to the plants. Though the two sides of the tank get lesser light than the centre (assuming both tubes are positioned at the centre), the amount of light is sufficient to most plants. Of course, a well balanced CO2 & fertilizer dosing will prevent algae from appearing.

[stocker]

If I'm not wrong, the 20W T12 Japan made tube is actually shorter than the 18W T8 commercially available tube. I found this out when I was seeking a commercial replacement for my Jap light. Those 18W T8 tubes were too long and the 20W T12 tube were not cheap either. So I ended up DIY-ing my own lights using the commercially available 18W T8 tube and reflector. I have one tube on a 2ft low-maint tank.

[andrewtyr]

2X15W FL is insufficient for most plants on a 2ft tank. A 55W T5-size PL (tube length is 2ft) is the least you should have. A 2X36W T5-size PL will give a lot of wonders to the plants. Though the two sides of the tank get lesser light than the centre (assuming both tubes are positioned at the centre), the amount of light is sufficient to most plants. Of course, a well balanced CO2 & fertilizer dosing will prevent algae from appearing.

yep, I'd second on that. However, 55W 8K lights is overkill, low tech plants will grow spotted algae.

[gregorsamsa]

hey,

i appreciate the concern that 30 watts is a bit low, that is why i have planted such that the front is low light demanding plants such as tenullus.
the stemmed plants like stelleta are growing albeit slowing at the back of the tank where the light set is at.

from my observation, i dont have to fertilise as much. while spot algae does occur, hair algae BBA doesnt appear.

My main concern is that most tubes dont cover the whole length of the tank thus have dark spots at the sides. I have anecdotal evidence that a 2x36 watts light set also face the same problem of plants from the side moving to the centre.

so far i have come to the conclusion that to prevent the problem, i either have to use t5 sets, or get a DIY hood of 18 watt tubes.

regards

[stocker]

A good reflector will nmitigate your problem somewhat, those commercial types are nice and wide...

[confusekid]

Have you think about HO T5 tube? Tube length is 55cm.

Jack

[rijac]

if you use 2 single lamp casings, you can 'stagger' them... i.e instead of putting them side by side.. you put one that covers 2/3 of the leftback of the tank and the other one covering 2/3 of the front right of the tank.. then you will only have 2 darkerned corners... (put java fern lor....)

my two cents.

[Sleepy_lancs]

Use more than 2 tubes... for myself, I tested with 3 x FL tubes for my plants.. its okay... 4 x FL would be excellent. Besides, this also ensure full coverage of the tank and less intense on central spot.

[soltari007]

Reflectors? Where to get them?

Noob