Add on another light or replace

[larlee]

Hi all,
I need some advice.
My current 2 ft tank is using a 2ft PL 55w light.
My Masilea is growing longer and I feel the current light set is not strong enough. Downoi is also growing upwards (long stem)

Tank Spec:
60x36x36cm
Plants: masilea, flame moss, xmas moss, US fissidens, taiwan moss, downoi, crypts

Should I get another set of 55W PL to add on or get a set of 2x24w T5HO to replace the current set?
the T5HO light set comes with 2x24w 10k tube, do I need to change it to a lower rating like 6500k or 8000k?

[jacian]

The 2x24w T5HO works out to be 48w, I do not think it will be much better than your existing 55w.
Yes, you will need to replace the 10,000k tube, my preference will be 6500k tube.

[Shadow]

I grow masilea and glosso in 2ft tank with 55W before, they creap. Maybe your light nearing its end of life? by the way I'm also using 6500K at that time.

[ct13]

My tank is 90cm x 45cm x 45cm

I am using 2 x 36W PL light. My gloso, masilea creep very well. I also have downoi, gujing in my tank.

I think you should change your tube, normal lifespan if the PL tube maximum is 1 years. I always change it after 6 months.

Hope this help.

[larlee]

Sorry if I missed out the intention.
My Masilea creeps but I want it shorter.
My current PL tube is only 3 weeks old. The previous one is spoil (3months old)and replace with a new tube.

I understand the numbers 55w is higher than 48w but what I want to know if PL lights can penetrate the water deeper than T5HO tudes?

[ct13]

48w will not penetrate deeper than 55w.

[larlee]

I understand 48w will not penetrate deeper than 55w

I am trying to compare between 55w PL and 2x24w T5HO lights, which will go deeper?

[ronang]

55w PL will definitely penetrate deeper than 2 X 24W T5HO with similar reflectors.

2 X24w will have more spread as actually, 24w per tube is max power for the throw of light. I have proven this with a light meter with sensor enclosed in a 30cm tube pointing at the light source.

Buy a good tube like a Osram PL55 865. China no brand tubes vary in quality. Clean the acrylic lens too.

[Salphur]

Hi,
like what ronang has mentioned... PL gives a very concentrated focus light straight down the tube with rather poor spread of light to all areas of the tank... T5 has a comparatively a better spread of light vs PL, however i am not too sure about light penetration though.

I am also using a PL 55w for my 2 feet tank and i do encounter such problems like my rotala sp green not 'creeping' under my PL light.. maybe due to PL tube not much mileage left..

Anyway, i do think you may consider using a Phillips brand as compared to Osram tube... cos the newspaper a few years ago did a comparison of light efficiency and effectiveness... Philips seems to do better with more 'ticks'.. haha... just sharing what i know.

2 other factors to consider:

1)Are the glosso and marsilea grown directly below the lightset or some other corners or areas where to light is not strong enough due to poorer spread?

2) The fertilising regime? I suppose when my dosing of ferts either irregular or not enough...my plants seem to grow a bit more uglier.. such as not creeping, long stems and distance between is leave nodes becomes more.

Let's hope your plants get better!

Cheers!

[larlee]

They are nicer under the PL lights but when it reaches the tank wall, it grew longer and looks ugly.... might be like what you say, it might be PL gives more focus in 1 area.

[Aquaculture]

There are pros and cons to switching to T5. Yes, it would give you enough spread to reach the sides of the tank but again it would invite GSA on the walls of your tank. Personally, I prefer T5.

[ct13]

My tank is 3ft x 1.5ft x 1.5ft, I am running 2 x 36w PL light in straight row and in the center of the tank.

My marsilea(top left) & glosso (front) are creeping very low to the ground. When I use 2 x 39W T5, they do creep well but start to have lots of hair algae (plants) & GSA (tank wall). Fert deficiency?? Anyone can advise?

So please consider before you change from PL to T5, unless your tank depth is 2feet depth.

Hope this help.

This taco position is 1.5cm front the tank wall, and it is left side of the tank.

[PlAnTaNoOb]

maybe its the spectrum rather than the type of light? What were the spectrum of ur T5HOs?

[blue33]

Did you check your CO2 enough? You may have high lighting but not enough CO2 and nutrients for the plants! Algae and other nutrients deficiency will appear.

My 2 cents!

[blue33]

You may have high lighting for the glosso and marsilea to creeps but other plant will suffer for it without high nutrients need for other plants.