Can Water Evaporation Damage Fluorescent Bulb? - Page 1
Forum section: electronics / beginners

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 04, 2011, 06:55:11 pm
content: Hello, i have got an aquarium several months ago which came with this 9W fluorescent bulb not working:The container which seals with plastic cover was 3/4 full of water which in my opinion explains half of it colored yellow.I later replaced it with 15W fluorescent bulb which worked for a little over a month and today stopped working:You can notice a little yellow color here as well.Question:When lightbulb was on for a long time, i felt heat coming from plastic which also raised water temperature by 1C. Could water evaporation in bulb's container be the cause of bulb's malfunction or it was just bad bulb or 6 additional Watts output? The container's "ceiling" is shiny and i don't know if it is metal or steel, but it is burned.This is how the container looks. You can see plastic seal as well:I also want to tell that weeks later i have noticed that rubber which is placed on plastic cover had gaps on both sides and today i used white silicone to fill them with:Question:I used silicone 8 hours earlier today and it still feels not that sturdy. Should i assemble plastic cover back or wait until silicone is fully sturdy?Thank you for your answers beforehand.

author: IanB
author_rank: Super Contributor
timestamp: November 04, 2011, 07:03:39 pm
content: Water should not be anywhere near or inside a light bulb. That obviously is going to cause problems.Also CFLs like that generate heat. They need to have venting and air circulation around them for cooling.The design of your aquarium seems wrong. I presume the bulb is in the lid? There should be vents above the bulb to allow air circulation with the outside. This will also allow any condensation to evaporate.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 04, 2011, 07:06:39 pm
content: The bulb is inside the container sealed by plastic cover. Do you have any suggestions as what can be done to fix the flaw of such design? I think if i will buy another bulb with 3 years warranty, i will have to change it frequently and drive dealer crazy.

author: Achilles
author_rank: Regular Contributor
timestamp: November 04, 2011, 09:02:58 pm
content: Quote from: Boris_yo on November 04, 2011, 07:06:39 pmWell, what IanB said is right. I suppose you have a heater in the Aquarium and all that stuff. So the Air Humidity above the Water surface (in the Tank) is very high and probably the sealing is not that good. The brown plastic should be from the bulb I guess. Just because it is built like that it doesn't have to be the right way to do it .....First off, I would suggest to drill some ventilation holes in the top cover, so that the heat can dissipate. Keep that away from the bulb-side and you won't lose much of the reflector. You may also think about some silicon (the proper aquarium silicon) and glue the plastic cover in place. I think you don't need much there.Another thing apart from that: I suppose it is a bulb with additional UV-Rays? I don't have an Aquarium but some Vivariums and the Bulbs (which act as UV Source) need to be replaced quite often, even if they are not broken, because they loose a lot of their UV-parts.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 04, 2011, 09:47:03 pm
content: Quote from: Achilles on November 04, 2011, 09:02:58 pmIf i glue plastic cover i won't be able to replace bulbs later. How to check if bulb has UV-Rays?

author: Achilles
author_rank: Regular Contributor
timestamp: November 04, 2011, 09:58:41 pm
content: You shouldn't fill all with silicon......just a little bit around on the joining surface. When the bulb is really burnt you cut off the silicon with a knife.Normally your supplier should know that. I don't know how much there is about with UV Light and aquariums, but at least the plants need some light (usually a normal fluorescent lamp has some small amounts of UV, too).I think you may get a clue if it is normal or a UV additional lamp from the color of the light.The light tends to be a bit violet then. Your local aquaristics supplier may know more about that.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 05, 2011, 08:10:57 am
content: Quote from: Achilles on November 04, 2011, 09:02:58 pmNo i don't have heater, nor do i have live plant but artificial plant. Aquarium size is 4.5 gallons.Please take a look at picture below:I am not going to drill plastic of course but aquarium's top. Where do you think should i drill holes as indicated on pictures and how many holes?Do you think it would be wise to install one of these computer's coolers and of which size? (Left one is smaller than right one)

author: sonicj
author_rank: Frequent Contributor
timestamp: November 05, 2011, 09:34:52 am
content: personally, i would start with something like this: *see attachthe discoloration on the bulb & plastic is the area of your primary temperature problem. placing holes above this area allows heat to rise and escape as cool, fresh air is brought in through the ends. i think convection alone should provide sufficient airflow. if not, you can force air via the fan.-sj

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 05, 2011, 11:43:23 am
content: Hey thankssonicj! I was looking for that explanation. Question is, should i create all holes in the beginning, middle and end or just beginning i.e where discoloration occurs? Also what should be diameter of each hole?By the way, what program did you use to add holes to existing ones?

author: Zyvek
author_rank: Regular Contributor
timestamp: November 06, 2011, 12:06:16 am
content: How about a cheap LCD light instead, something like this:http://www.dealextreme.com/p/e27-1210-6w-84-led-588-lumen-6500k-light-bulb-white-85-265v-ac-35829

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 06, 2011, 04:30:37 am
content: Quote from: Zyvek on November 06, 2011, 12:06:16 am6.2 cm x 3.7 cm x 3.7 cm are dimensions. But what is the diameter? Is it 3.7 cm?

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 17, 2011, 07:28:20 pm
content: One fishkeeper told me that even with holes the bulb's socket might burn. Aquarium wholesaler technical support told that the bulb's wattage is incorrect. I used 15W instead of 9W which broke before, but maybe higher wattage was the actual cause with 15W bulb?

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 27, 2011, 10:22:53 pm
content: I was offered bulb 2 times the standard cost but with 3-year warranty. I just wonder how bulb will operate after holes are drilled and convection is established. What if bulb will get burned often? The dealer will notice this and ask how can 3 year warramty bulb burn that often. He will refuse to replace since such lamps should work 3 years.Or i can buy half price standard bulb like i did first time with 15W bulb that burned which is more than a 9W bulb that came non-operational with the aquarium. This one however does not have warranty.Whatdo you suggest guys i should do?Thanks.