one of my tanks currently up and running is a juwel rio 125 my main question is it has a dual lighting system with 2 18 watt day glow tubes. this tank is about 14 months old and the lighting does not seem to be as efficent as it once was is there a recommended lifetime for these tubes and how often should they be changed any help greatly appreciated....... :?: :?:

every 10 months

hi steven
panda is right, best to change bulbs atleast every 10 months as the spectrum burns out (kinda like candles, they loose there intensity) they can last for years but are no good for plants and you may find you grow alot of algae!
if you have the standard juwel bulbs i would always change them to better bulbs anyway, IMO

i agree...at the moment im using interpet daylight plus bulbs. youd be suprised how differnt the colours (ofyour fish and plants) look wit hdifferent lights. zig is the man when it comes to lights...
check out this post

www.irishfishkeepers.com/forum/viewtopic.php?t=136

Personally i think it comes down to personal viewing preferences when looking at your tank, a lot of emphasis is placed on the colour temprature of various tubes (the colour of the tubes output measured in degrees kelvin or k) but this is only one factor that should be considered for example, it is widely regarded that tubes between 5500k and 6700k are in the best range for photosynthesis to take place, but this is really only a generalisation as different manufacturer's 6500k tubes will have very different spectral outputs, in other words one manufacturer's tube will vary widely from a different manufacturer although both will claim their tubes are 6500k, and if you compare the spectrum graphs and you will find that this is the case.

Its generally regarded nowadays that light intensity is more important than colour temprature, basically as long as there is enough light produced, plants will grow.

Any tube between 3000k to 14000k will grow plants as long as most of its output is in the red end of the spectrum and only a little in the blue end, tubes that have their main output in the blue end of the spectrum are not recommended, these are mainly for marine setups, tubes with there main spectral output in the blue end of the spectrum will cause algae growth in a freshwater setup.

Heres just a basic rundown on some tubes i have used and the different colour hues they give for viewing purposes.

Interpet Daylight Plus-6500k-cool white (very good light for viewing purposes IMO)

Interpet Triton/Triplus-8300k-White purple

Arcadia Freshwater-7500k-White green

Arcadia Origional Tropical-?k-Pink (avoid, light intensity is also low)

Hagen Life-Glo-6700k-Bright cool white

Zoo Med-Tropic sun-5500k-Warm white

Zoo Med-Ultra Sun-Bright cool white

ASL Daylight-7100k White with tint of green (using these ATM)

ASL Freshwater Tropical (powercompact) 7100+8000k White and pink mixed.

I have used all the above with prettty good results, normally these days i will choose tubes based on the colour output for viewing purposes and i always use good reflectors, if you choose tubes between 5500 and 7000k you cant go far wrong IMO.

HTH

Hi Steven,
sorry for the late reply. I've been out of the country for 10 days.
You can do this cheaper. Go to any electrical supply store and get one warm white and one daylight tube. This will do perfectly well and they cost about 3 Euro each. You might have to change the connections in your hood slightly since Jewel use non standard tube length. I guess they want to make sure that you buy the tubes that are specially made for the aquarium trade.
The optimimun temperature to grow plants is about 6800 k.

Holger

fair play to you guys have change them since i posted and things are looking like they used to cheers lads