PL Lights Question

[mkt]

How often do you guys replace the PL tubes?
Wonders how long before it dims...

[chua]

I personally feel that PL tube will become dimmer and dimmer.

You will only start to notice maybe after 4-6 months.

Whether you want to change or not depends on the plants you have.
Some plants need more light hence you will need to change the tube above that plant more frequency as compare to less light demanding plants.

Maybe you want to share the types of plants you have with us.

[tawauboy]

[quote:061a6de4fe="mkt"].......
Wonders how long before it dims...[/quote:061a6de4fe]

the light tube will be dimmer progressively. quite hard to notice it as you are looking at it daily. you will notice the difference when you change the tube. generally, pl tubes are changed at every 9-12 months interval.

[bclee]

Most good tubes loses about 10 -20% of the brightness during the initial burn-in (probably first few days/weeks). After that, the brightness remain quite constant, dimming slowly, until it is near the end of life. Cheaper tubes probably dim faster due to poorer quality phospor.

IMO, if you are using good quality tubes like Osram Lumilux or Dulux, the tube can be used almost to the end of its life which can be up to one-and-a-half year or two.

BC

[mkt]

[quote:7424192a7d="chua"]I personally feel that PL tube will become dimmer and dimmer.

You will only start to notice maybe after 4-6 months.

Whether you want to change or not depends on the plants you have.
Some plants need more light hence you will need to change the tube above that plant more frequency as compare to less light demanding plants.

Maybe you want to share the types of plants you have with us.[/quote:7424192a7d]
glosso, hairgrass, stargrass, elatine t., PP,
not so much pearls on the glosso nowadays.
KH 2-3, PH 6 , tube from osram 36 W x 8, 4' tank

[vinz]

In general, you should replace PLs every 12months, but to replace all at a go might throw your tank off balance, as you will suddenly have much brighter lights.

Change the tubes in intervals. For example, if you have 2 rows of PLs, then change one row at the 6th month and the other row at the 12th month, then change the first row at the 18th month, etc. If you have 3 rows, you can change one row every 4 months. This will help to keep the light levels fairly consistent.

It'll help if you get a marker and write down the date of the change on the new tubes. Also, shift the newest row to the front, where the foreground plants need it most.