T5 Fixture Question

Donya

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I have a deep blue solarmax 2xT5HO+LED fixture on my 55 gallon tank. It has served me well thus far, but it finally came time to replace the bulbs since I got the usual cue of the tank suddenly growing great gobs of hair algae in the refugium instead of the normal great gobs of chaeto. My problem is that I wasn't able to put the fixture back together the way it was before replacing the bulbs.

Out of the box, this fixture had a plexiglass/acrylic/some plastic cover between the bulbs and whatever the fixture was to sit on. Unfortunately, although I was able to remove the old bulbs by just taking the ends off the fixture (which is the only way into the thing - the ends also keep the cover from budging), I couldn't insert the new bulbs and get them working with this cover in place. Trying to insert the bulbs in the way the old ones were loaded, sitting lightly in both removable ends, meant they didn't turn on when I flipped the switch. The old ones somehow worked without the usual quarter twist fluorescent fixtures require, but the new ones absolutely need it. I see no way to both twist the bulbs AND replace the plexiglass cover unless I do the seemingly dangerous and stupid approach of "locking" one side with the twist, putting the cover on, and then just pushing really hard to force the pegs of both bulbs simultaneously into already "locked" openings on the other side. I just don't feel comfortable with that method even though I have now read some accounts of others doing exactly that out of frustration. Seems like a great way to break a bulb or two if anything slips and possibly give my hand a good injury since the metal edges aren't exactly smooth.

Making things slightly worse, then I attempted to slide the cover out as it was obviously meant to, it snapped. There was a slightly wider spot that apparently hadn't been sanded down properly. It stuck and caused it to split under very little tugging. Not a huge problem in itself since I have gotten rid of that wider irregularity and can slide the two halves in and out still while managing a pretty tight join if I really need to put them back in there (assuming I actually can without telekinesis). Unfortunately the instructions have taken a hike so I can't confirm whether I'm recalling them wrong, but I really see no way to put the thing back together the way it originally was - assuming I want the lights to turn on!

Cutting to the chase, I am now running this fixture cover-less. The main reason for this is that I want the tank lit while I have a think about what the heck is going wrong. The tank has a glass canopy, so this is essentially the arrangement I am familiar with for all of my other fluorescent fixtures: no cover built into the fixture, but a cover over the tank keeping everything safe (I was actually a bit surprised this one had an extra cover). Additionally, the fixture is running distinctly cooler now, almost certainly due to the extra bit of air circulation allowed by not having the cover on, so I'm wondering whether to even try putting it back.

So, fellow salties who may have seen this kind of fixture issue before: yay or nay on leaving it cover-less and just relying on the glass canopy for protection like I do for all my other fluorescent fixtures? Is there some massive benefit to that plastic cover that I'm not seeing?
 
Donya, i'm being a bit thick here, but cant picture what you mean, can you post a photo?
 
I have thus far managed to forget to take a photo of the fixture each opportunity I've had, but here are some super-realistic MS Paint representations lol! I will still try to remember to get actual pics.

In cross section, the fixture looks pretty much like this:

fixture_xsect1.png


The acrylic plate is what I broke and then couldn't figure out how to put back after bulb replacement, so it's been left off. As it turns out, it was actually blocking most of the output from the moonlight LEDs (makes me wonder how much other light it had started blocking) due to apparently yellowing a bit, so I definitely don't want to put the broken one back in. If I need to replace it I'll have to see about getting/making a new one.

At any rate, the whole fixture sits on a glass tank cover - so even without the acrylic cover there is no exposure of the bulbs to salt splash - they are totally dry all the time. Since I have other fluorescent fixtures that don't even come with an acrylic cover, I'm wondering what the purpose is if the fixture is already protected by other means?

Regarding the horrible issue of how to put it back together, the ends of the fixture look about like this (looking up from the bottom):

fixture_end1.png


The ends of each bulb are protected by cylinders/holders that they slide into. So, the bulbs have to be slid into these holders all the way (which isn't all that easy since it blocks visibility of the pins) and then twisted 90-degrees so they make a good connection. The acrylic plate, if present, would cover up the entire open area and would have to be inserted with at least one of the ends removed. Once inserted, there is no way to get a hand into the fixture to twist the bulbs. The whole darned thing would make sense if you could bend the acrylic cover a bit without it breaking and pop it into place after the bulbs were in and twisted...who knows. If I have to get a replacement cover I'm going to aim for that sort of idea, since the "solution" I read about of forcing the bulbs into the holders in an already rotated position is madness. I actually wonder now if that's what was supposed to happen and maybe the material has just become brittle over time in addition to picking up a tint.
 
Finally! I can be of use. T5s being my thing. If you've got a glass cover, you can run the fixture without the acrylic. They ARE sometimes hard to put back! Haha, have snapped one or two myself. The cover is more for moisture protection if you are doing an open top tank.

Ran a broken one like that for a few years in another tank. Worked fine. My only concern is possible salt corrosion, but that's often a problem with SW systems regardless. Live in FL, salt kills cars.

Does this help?

Liz
 
Finally! I can be of use. T5s being my thing. If you've got a glass cover, you can run the fixture without the acrylic. They ARE sometimes hard to put back! Haha, have snapped one or two myself. The cover is more for moisture protection if you are doing an open top tank.

Ran a broken one like that for a few years in another tank. Worked fine. My only concern is possible salt corrosion, but that's often a problem with SW systems regardless. Live in FL, salt kills cars.

Does this help?

Liz

Awesome, thanks! Did you have to buy/make replacements for the ones that broke, and if so how did you go about it? Also, how do you handle the issue of the bulbs needing to be rotated into place?

I'm going to keep an eye on the salt as it does tend to get everywhere, but I recently picked up a used T5 fixture for another tank that was exposed to similar conditions without a cover for years and doesn't have a speck on the insides yet, so I'm hoping that if I keep up on my cleaning of this one that it will be ok (but will be keeping a close eye on it!).
 
Donya, when the acrylic broke, I never bothered to replace it.

As to your other issue with the bulbs not fitting. When I stick my T5s in the fixture & give the bulb the quarter turn to lock them in place, I've never had a problem with the acrylic not fitting. I'm trying to now remember how the acrylic broke in the first place.

But I see no problems with continuing to use the fixture.

Liz
 

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