T5 light

I have recently removed one bulb from each of my T5 HO fixtures and found that my plants are still doing great. I did it because of algae issues in a few tanks. The thing I am wondering though is, with one bulb removed will the fixture still use the same amount of power? I am hoping that it would reduce power consumption.
Thanks!

That is interesting. I have one bulb removed from one of my lights myself (laziness, not for any other reason) and I never thought about its power consumption. Just guessing, wouldn't removing 1/2 of the bulbs make the fixture use half as much power? Any electricians out there?

That is interesting. I have one bulb removed from one of my lights myself (laziness, not for any other reason) and I never thought about its power consumption. Just guessing, wouldn't removing 1/2 of the bulbs make the fixture use half as much power? Any electricians out there?

That's what I am thinking/hoping. I started wondering though if the ballast would still draw the same amount of power regardless.

I just bought this but have not tried it yet. It is supposed to measure the actual energy usage. You can measure every device in your home on and off (some things actually stay on when shut off). People say they find surprises. Seems like a handy thing to have and certainly would answer your question about your aquarium lights. Very inexpensive but does take some work to calculate the final savings.

Example comment: My air purifier, which I bought here on Amazon, uses 85 watts all the time... 85 * 24 hrs * 30 days / 1000 watts = 61.2kWhr * $0.20 = $12.24 a month.

Another comment: I found that hitting the switch on the surge supressors of my computers at night can save me almost $5 a month off my electric bill.

Another comment: Opened my eyes to many hidden drains and surprised me at how little some things use as well. ie: 18v battery bank charger for my cordless tools uses nearly half a kilowatt a day!

Tracking the usage comment: How did I figure out usage? I created an Excel spreadsheet with the following columns: Device, estimated wattage, estimated hours/month, kilowatts avg/month, measured kwh/day, measured kilowatts, annual cost. I went through the house and inventoried everything I could find, entering it into a row of the spreadsheet. Then I filled in the estimates: >- Hours/month: if I use a TV 3 hours a day, I enter the formula 3*365/12; if I use a treadmill 45 minutes on 10 days a month, the formula is 0.45*10*365/12. - Kilowatts (average over the month): formula is watts*hours/(24*365/12)/1000. If you have a 60-watt light left on 24/7, you should see the value 0.060; if you have it on a 12-hour timer, you should see the value 0.030. - Annual cost: formula is kilowatts*365*24*cost. Locally the cost is 13.5 cents so a 100-watt device works out to $118.26 per year.

I think we might be surprised at some of the things we use every day and what it costs us a month or annually. I think I am going to start with my filter and then the air pump. Then the LED lights I made. It might be good to do a comparison among ourselves to see what is efficient and what is costly to operate.

http://www.amazon.co...=cm_rdp_product

I will post some results when I have them.

Usil

Edited by Usil, 08 December 2011 - 02:46 PM.

The power draw from the missing tube will be gone.
Your power draw will be one tube + the power consumed by the ballast.
Heavy, buzzy/humming old style electromagnetic ballasts typically draw 12-14w, much of which is lost as heat. Electronic ballasts draw a pretty negligible 2-4w.

Rick

It might not be as simple as that. It depends on the design of the fixture. Some flourescent fixtures will use as much or more power with a dead or missing light than with the lights present.

It might not be as simple as that. It depends on the design of the fixture. Some flourescent fixtures will use as much or more power with a dead or missing light than with the lights present.

That made me curious, so I did some research and you appear to be correct. The website http://nemesis.lones...cent/rapid.html says,
"Because of the design of a Rapid Start fixture, the fixture will consume power if the lamps are unable to start because one or more of the lamps have been removed or rotated so that it does not make electrical contact with the socket. This is because the ballast will consume power trying to start dead or electrically missing lamps. The worst case situation is to have at least one lamp still in place, as the cathode filaments will continue to receive current for heating the filaments in an effort to get all the lamps going."

Looks like I'm putting that extra bulb back in when I get home today.

I wouldn't make it a rule of thumb.

In some fluorescent fixtures having a dead or missing lamp will also reduce the lifetime of other components of the fixture including the remaining lamps.

Well designed fixtures will probably not care one way or the other and will function just like rickwrench says above. It all depends on the specifics of the fixture.

Alternately, you could simply leave both bulbs in and cut your light cycle a few hours a day...

2 minutes resetting the timer sounds like an easy fix. That way, instead of removing the bulb and getting lost in all the questions and possibilities involved (and the risk of having an unprotected bulb laying around), you unquestionably cut total light input and power consumption.

My WAAAAY overlit, 14w cfl over 2g pico/nano runs on 8 total hours of light a day, 9:00am-noon, 4:00pm-9:00pm with no algae problems. At 10 hours a day, it was a problem.

Concerning old analog rapid start systems; fortunately, the bad old days of buzzing 1940's tech electromagnetic ballasts and flickering 60Hz, UV-a bleeding fluorescent fixtures are (mostly) over.

T5-HO fixtures have electronic ballasts.
-Most- of them are programmed start with built in end-of-life circuitry to shut off the start/heat circuits in the event of a dead or missing bulb.
The current specs also call for 40+kHz frequency, as some of the older 20kHz frequency ballasts messed with TV remote controls. 60Hz flicker headache is just a dim distant memory.

For those that absolutely must have the aquarium light on all the time during waking hours, there are several excellent (though still expensive right now) dimming capable ballasts available for T5-HO lamps on the market lately. Anyone that can tell a screwdriver from a rock (and can read), should be able to retrofit one into an older T5-HO fixture.
Then, using a PAR meter or even just week-at-a-time algae monitoring, you could dial in your exact light needs, set your dimmer, light timer, and forget it.

That "forget it" part has always been a key feature for me in any aquarium set up.

Rick

No, the power will recirculate through the circuit and into the other bulb. Half the power would be used, though a small power loss may be observed due to electrical leakage.

Thanks!

Fascinating. That seems pretty weird that the ballast could waste power trying to start a tube that isn't there. I wonder where the wasted current is going? Obviously not through the sockets, if there's no tube installed.

I have a couple of old lights that only work if I rotate one prong OUT of the socket after it starts. Otherwise the starter doesn't know when to quit and just keeps firing, making the tube blink. (I dont use these fixtures often for obvious reasons; just keep em around for short-term use, and for curiosity's sake).

That made me curious, so I did some research and you appear to be correct. The website http://nemesis.lones...cent/rapid.html says,
"Because of the design of a Rapid Start fixture, the fixture will consume power if the lamps are unable to start because one or more of the lamps have been removed or rotated so that it does not make electrical contact with the socket. This is because the ballast will consume power trying to start dead or electrically missing lamps. The worst case situation is to have at least one lamp still in place, as the cathode filaments will continue to receive current for heating the filaments in an effort to get all the lamps going."

Looks like I'm putting that extra bulb back in when I get home today.

Fascinating. That seems pretty weird that the ballast could waste power trying to start a tube that isn't there. I wonder where the wasted current is going? Obviously not through the sockets, if there's no tube installed.

I have a couple of old lights that only work if I rotate one prong OUT of the socket after it starts. Otherwise the starter doesn't know when to quit and just keeps firing, making the tube blink. (I dont use these fixtures often for obvious reasons; just keep em around for short-term use, and for curiosity's sake).

The ballast does two things. First, it provides a capacitor electrical storage for the "jump start" energy required to initiate electron flow through the bulb. Second, it limits the flow of electricity (via resistors) in order to prevent runaway electrical flow through the plasma inside the bulb once electrical flow is started.

If a worn out bulb is in place, as the capacitor recharges, it can exceed the resistance inside the bulb, thus trying to start a dead bulb repeatedly. This is hard on the electrical components and creates heat (wasted electricity) from the electrical flow.

If there is one or more bulbs missing from the system, depending on the design of the ballast, the ballast may - and often will - shunt the electrical flow that would have gone through that bulb to the remaining bulb(s). This will cause the remaining bulbs to produce more photons, and will not save on any electrical bill. However, for these photons to create visible light, they impact the florescent coating on the inside of the bulb, causing it to emit visible light. (This coating is what provides the different light wavelengths that we are concerned about). As this coating is finite, there is only a limited number of photons that will absorb into the florescent compound and convert to visible light, and the remaining photons (thus electricity) is wasted.

If there are no bulbs in the fixture, the electrical circuit is not complete, and no electricity is used. However, if there are dead bulbs, there may or may not still be some limited electrical flow. And, of course, if the switch is turned off, there is not a complete circuit, so no electricity is used. So, it is best to have all lights filled and working properly, or no bulbs in the fixture at all, or the switch turned off. Also, due to the different resistances between old and new bulbs, it is often suggested that you replace all bulbs in a florescent fixture at the same time.

Worn out bulbs, such as what you are speaking of Gerald, may not be worn out at all, but instead the ballast may be worn out. Worn out ballasts can overheat, and yes, they CAN cause a fire, but are suppose to burn the circuit out before a fire is caused. And leaving one prong out of the socket is an electrical and fire hazard. (What you are doing is essentially increasing the resistance in the ends of the bulbs, which creates heat). I would avoid doing this in the future if I were you.

As for what happens to "wasted" electricity, it is just that. Through resistance of electrical circuits, it is converted to heat, and in this case is considered wasted electricity. (In an electrical cooking range, the resistance of the coils converts electricity to heat, and when they turn red, this light is considered wasted electricity since it is now light instead of heat). Heat will shorten the life of your light fixture and bulbs.

And finally, the reason we recycle florescent bulbs is that there is a small amount of mercury inside the bulb. This mercury becomes plasma when the bulb lights, and then reverts to normal state when the light is powered down (and either coats the inside of the bulb or is often held within a powder in the bulb). Thus, the warning to not break the bulb, which can release mercury into the air. Now, if you are concerned about your high dollar aquarium fishes and the mercury, there are protective tubes you can install over the florescent tubes in a fixture. They may not prevent 100% of the mercury being released in case of a broken bulb, but they will drastically limit the release, and will contain any glass breakage, and are cheap!

In conclusion, it is best to maintain working ballasts and bulbs in your light fixture. This will prevent wasted electricity and extend the life of your fixture and bulbs.

Okay, so the fixtures that I am leaving one bulb out of are a couple of Aquatic Life T5 ho and one Current T5 ho. They are all pretty new 3 years or less. They do not feel any warmer. Is it fair to say that these newer fixtures are fine with one bulb out? They seem to be working fine.

What about removing the wires connected to the light socket and ballast, would that solve the issue of electricity waste?

Edited by Elijah, 12 December 2011 - 03:28 PM.

What about removing the wires connected to the light socket and ballast, would that solve the issue of electricity waste?

Don't mess with your light. You could wire it wrong and start a fire.

Oh I take apart lights and convert them from one type to another. CFL-T5. I used to wire electronics as part of my former profession.

Okay, so the fixtures that I am leaving one bulb out of are a couple of Aquatic Life T5 ho and one Current T5 ho. They are all pretty new 3 years or less. They do not feel any warmer. Is it fair to say that these newer fixtures are fine with one bulb out? They seem to be working fine.

What about removing the wires connected to the light socket and ballast, would that solve the issue of electricity waste?

Removing the wiring will be no different than just leaving the bulb out.

Rickwrench posted that "T5-HO fixtures have electronic ballasts. Most of them are programmed start with built in end-of-life circuitry to shut off the start/heat circuits in the event of a dead or missing bulb." Your ballasts probably have this circuitry in place, and thus will limit the losses. Yet, this cannot be guaranteed without looking up the circuitry diagrams or design characteristics of your ballast. Google your ballast or contact the manufacturer to see.

Google your ballast or contact the manufacturer to see.

That would certainly settle the question!

Rick