Tina's Twin Bommies

[SkiFletch]

Depends. What are the tank dimensions again, and what's your planned lighting? PC's waste a lot of their light with the tubes so close together and the lack of individual reflectors. If the tank is shallow, they're sufficient for a good deal of corals, but if it's deep, they're not the best choice...

 

[TigerIssey]

This tank is 39" x 15" x 18" (lxdxh)

The 6ft I am looking to buy will be 74" x 24" x 18" (lxdxh)

I am waiting till the new TMC arrays are launched to see what they are like. Want to supplement the PC's in the 6ft with LED lighting. Did not want to go halide, hence keeping the depth of the tank to 18".

 

[SkiFletch]

So you want to use 2x55 and 2x36 watt PC's on a 6' tank and suppliment it with LEDs? Hate to be the bringer of bad news, but that's gonna be way underpowered TI .

 

[TigerIssey]

No there will be 4x 36w as well as the 2x 55w. I may need more??

The lengths of the bulbs cover the tank so that there is 2 bulbs, 2 bulbs, 2 bulbs, was looking to have different strength lighting along the length, unsure which wattages to put where yet. The new Arrays are supposed to be comparable to halides. Will need to see about that.

 

[SkiFletch]

Wellll, I dunno if I would do it, but you might be able to get away with it...

Here's the thing, a little education about PC lamps. They were "supposed" to be the savior of lighting. Cheap to manufacture, built on an existing technology, efficient in electrical usage, and high power output. Except people who designed them just wanted marketing $$ and didn't care that they were violating all kinds of laws of optical physics.

All PC's are is a streched out T5 tube which instead of passing current along the tube from end to end, passes it from the base to one end, around the loop together, and then back to the other side of the same end. The "wattage" of any flourescent lamp is dependent directly upon it's diameter and length, so a PC packs two T5 tubes together in the same length for double the wattage than a comparable single T5 tube. One problem though... They're so close together that you cannot build a reflector that functions in between the tubes of a PC lamp. So all the light output between or even vertical from the tubes is wasted bouncing back and forth between the tube glass instead of being reflected down on the tank. In the end you loose almost half the PC tube's light bouncing around in the reflector and between the tube and it is all of a sudden only a tiny litttle bit better than a single T5 tube with a good parabolic reflector of the same length.

So if you have a tank with sets of PC's to gover the length of the tank twice, you're only a little better off than having two individually reflected T5's spannign that length. And while that light will be "sufficient" for low-moderate light corals such as you currently have, you won't be able to get into the high-light stuff. AND you're wasting electricity running with PCs...

My suggestion would be to find a 6x39watt T5 setup with individual reflectors. That way you can have the 36" tubes end-to-end and thus have 3 individually reflected T5's spanning the length of the tank. Doesn't use a lot of energy and would give you plenty of punch for an 18" deep tank.

JMO

 

[VictorMeldrew]

Lovely pic's mate

 

[garry_boyd3]

Hi, a little of subject but how often do you feed your hairy mushroom. Fed mine last night brilliant to watch Thanks.

 

[TigerIssey]

Right Ski, gonna take some time to think about this.

The problem I have with T5's that span the length of the tank is that each bulb is £30+ and then you have 6 of them. Part of the appeal of the PC's is that the tubes are much cheaper to be replaced so often.

Part of me is now thinking to supplement with a couple that run the length of the tank (obviously the depth being 2ft I do need more). Part of me is thinking It may be worth the expense in the long run to supplement with enough LCD to count alot more, whether they be the current aquaray or the upcoming array.

I wish I knew more about the release and product details for TMC's new array lighting.

OR

I go down a similar route to Rabutt and build a high output LED unit that will supplement what I have.

If I had my compensation from work, I would just put the recommended amout of aquarays on and some PC's aswell.
Still do not like Luminaires either, the tank will be next to the TV so don't want any leakage of light from the front or sides. Going to leave the back open to allow air circulation.

Thanks VM.

Gary, I feed the Rhodactis about 3 times a week. It does not always take food however, if they curl up around the food, they are feeding, if they are not hungry, the clownfish get to what I am feeding first.

 

[SkiFletch]

Wow, 3' lamps are 30 quid? Yikes. They're only like $20 here...

How much are the 6 PC lamps?

 

[garry_boyd3]

Ski you thinking of doing xport?

 

[TigerIssey]

I can get the PC lamps for about £16 for 55w and £10 for 36w (can get them cheaper occasionally on ebay too). Compare that to £30 a tube for the T5 and its a big difference. I may get them cheaper by shopping around but then you lose what you have saved in delivery on the larger tubes. Don't know if its just by me but the longer tubes tend to be horrendously expensive.

 

[SkiFletch]

so about 84quid for lamps for the PC setup and 120 for the T5 setup. Pretty significant difference.

Lets do some math here though, that's a difference of 36 which you'd have to make up in energy costs over the course of two years. The PC's would run 292 watts with the T5's running 234, a 58watt difference. So assume 10hrs a day, that's 0.58KWhr/day, 365days per year that's 211.7KWhr extra. And then at a cost of lets say 0.13 quid per KWhr that's 27.52 quid saved per year for electric costs. Lamps would need replacing every 2 years which means you'd save 55.04 quid in electric but spend an extra 36 on the more expensive tubes leaving you with a total savings of 19quid in your pocket and a lot more light rays for much happier corals

 

[TigerIssey]

I thought T5 tubes needed replacing every 6 months.

 

[rabbut]

Erm, sorry to rain on TMC's parade here, but you need something like twice as many as they recommend to get enough light for what you want. For instance, TMC claim 6 units (about £600 worth of their units) would have given me the equivelant output of my old 150W halide over my 70l reef. Real "end users" of the Aquarays all said, about 12 units (£1200 worth) would be closer the mark, though still a bit less... Now, I don't have a PAR meter, but my LED's have nearly 5X the Lumen's output of my old halide, after throttling back the Blues a bit, and the whole unit, including computer controlled dimming and temperature management cost me about £300 in total... DIY ATM is far out-performing the Aquarays on cost and actual light out-put. Top this off with many Aquaray users recently reporting issues with the PSU's on their units, and you get a joke of an LED system TBF

The new units are supposed to be really good arrays, and equivelant to a halide. They said similar about the current units pre-release. I'm not optimistic. The fact they are Arrays surgests they should have better output, but you have potential for reliability issues unless they have learnt from the first generation, and LED technology has moved on since they announced these units, suggesting that the technology behind them is already "dated". Oh, and TMC's LED's don't have much spread either, they will revolutionise lighting, as you'll have to have all corals an equal distance from each other in a strait line to use them with the recommended number of units, unless you raise them a long way off the tank to widen the beam, but decrease the units power I thought about Aquarays, but DIY LED's are literally first year of high-school level electronics (i.e. basic) unless you want computer control, they it's second/third year level, and then it's only due to the programming (that's actually far easier Java code on the Arduino board I'm using..). considering the ease of application and the cost savings for better output, really there was little excuse to bother with the Aquarays. I mean heck, some of the cheap Chinese stuff on Ebay is better value for money than the current Aquarays IMO

If you did go DIY computerised LED's, I'd be happy to code the computerised bit for you, just leaving you to do basic electronics and mountings for it

If LED's are off the cards, I'd go the linear T5 route that Ski says though, since you don't want Halides

All the best
Rabbut

 

[TigerIssey]

T5 tube replacement, I am sure I have read is every 6 months. Can someone confirm this for me??

Rabutt, would I need computer control, not really bothered about dimming, will still use timers for actinics etc.

What would interest me is a shopping list of parts. That way I could look at what I need and what electronics I needed to do, then decide if I am up to it. I was good at electronics, but its been a while since I left school, having said that a BSc Honours degree in a science subject should mean I can sort out the putting together of it.

Thanks very much for the computerised offer bit. Would like it to be as simple as possible though, that goes for the whole tank setup to be honest. The simpler it is, the less can go wrong.