Light Reflectors - Double The Light?

[SuperColey1]

Does 0.6WPG LED count LLj?. lol That is medium!!!! believe me

I sort of agree with Truck but he is exaggerating quite a lot. I would suggest Good quality T8s are about 1.25x T12s

The simple equation here is pretty easy. Stand at the side of your tank get 2 rulers and place them from the edge of the tank where the water surface is up to the sides of the tube. How much of the circumference of the tube is within these 2 rulers? I would guess 30%. That is how much (rough idea) of your 40 watts is getting into the tank without reflectors.

Now think about reflectors. Top notch ones will retrieve almost 100% of the lost light however some of this light even with these top notch reflectors will hit the tube on the way back. So lets say we use standard curved easy to source reflectors we are now up to 70%, maybe not much more than this with the top top notch ones. More than double the light than without reflectors.

However we shouldn't ever look at this as double the light in comparison to the WPG rule. Think more of the WPG rule assuming that you are using reflectors and that it is taking into account restrike issues.

Therefore 1WPG with reflectors means 1WPG. 1WPG without reflectors means 1 / 70 x 30 = 0.42WPG.

So there you go If you do not use reflectors on 40W over a 33USG then you have 40 / 33 * .42 = 0.5WPG. simples init

I used to use 30W flourescent with reflectors and CO2 over a 33USG. You say low light. I say rampant.

I now use an average of 20W LED over the same 33USG and believe me it is definately Medium light

AC

 

[lljdma06]

Does 0.6WPG LED count LLj?. lol That is medium!!!! believe me

Oh, I believe you. I, still living in the cave, still use T5s. In that case, .5WPG is probably low. But I don't dwell on it. The .77WPG in my 36g gets the job done with no hassle. No CO2. No worries.

I now use an average of 20W LED over the same 33USG and believe me it is definately Medium light

AC

LEDs look great and I see them much more in catelogs now than I used to. The price is starting to drop too.

 

[SuperColey1]

Not living in a cave at all LLj. lol

If I had not moved from T5HO to LED I would've moved back to T8.

For our purposes (planted tanks)the lower light needs(* see explanation below) we have means that more T8 tubes are much better than less T5HO tubes even though it is the same wattage because it enables us to spread the 'W' out better.

*When I say 'lower light needs' as planted requirements I am talking versus the demands of reef which are a huge amount higher than a 'highlight' planted tank.

That is the reason LED is so much more succesful in that you can spread the light evenly rather than have the whole kaboodle fixed in 1 line as with flourescent. Therefore the more tubes you use to gain the wattage the more you can spread the W over the entire tank.

Why do I say I would go back to T8 and not standard T5 after all they are the same wattage at the same length. Simple: People have obsessed over T5HO and therefore standard T5 (T5NO) are very tricky to get hold of whereas T8 are easy to get.

The best flouros to use would be T5(NO). They are the most efficient and give you the option of using 2,3,4 rather than 1,2 T5HO.
With T5(NO)not being so easy to source then T8 is next best. They are more efficient than T5HO and also allow you the same spread options as the T5(NO) being a similar wattage at the same length.

This does of course assume that you use electronic ballasts with the T8s and not the oldie magnetic flicker start ballasts

Saying that, any light is better than none although I would suggest that compacts (PC/CF/PL) are right at the bottom being the last resort as they bang all the light into a tiny area and also are very hard to use with a reflector.

Any queries should be directed to Gordon Brown because he is the font of all knowledge regarding everything....ahem

AC

 

[lljdma06]

You have trouble finding T5(NO)? I have found them pretty easily, especially in more specialty stores and online. Hmmmm. Maybe it's a US thing?

llj

 

[SuperColey1]

You have trouble finding T5(NO)? I have found them pretty easily, especially in more specialty stores and online. Hmmmm. Maybe it's a US thing?

llj

T5(NO) are out there but T5HO sort of got in on the act before people had moved on from T8 over here. The options on T5(NO) are pretty limited in terms of range whereas there are many times more options for T5HO.

Always a problem in the UK that people always want the latest technology and very quickly what came before gets forgotten. Many T5HO tubes aren't labelled as T5HO, just T5 and therefore people seem to thing that all T5 tubes are higher power for the length than T8 which isn't the case.

AC

 

[Mikaila31]

I have relied on the U-shapped power compacts for my higher light tanks, not really wanting to get into the longer tubes. These are starting to be used less and less though with the straight T5's. I'm kinda facing the same issue with bulbs, but my issue is I can't grow stuff with T8's . IDK what my issue was with those bulbs, but none of my tanks use them anymore. I've retrofitted regular home store "daylight" 14watt spiral compacts into my fixtures. I really love these bulbs now. I know the are not very efficent with a lot of restike going on, but I had 2wpg of T8's with a white reflectors then switched to 2wpg of spiral bulbs with a metal reflector and the plants are so much happier. As a college student I'm sold on these bulbs. I can get 4 of them for $10. Also since they are individually ballast I am only limited to what I can fit in the fixture. Plantedtank.net also had a really interesting thread with some PAR values on spiral compacts. According to the data there is a very significant difference with the bulb positioned vertically or horizontally above the tank. Vertical provided much more light, I run mine all horizontally though to reduce the height of the hood...

 

[Deleted member 55926]

Was wondering about using foil for some DIY reflection. How do I do this? Just glue some foil to the underside of the lid?

 

[SuperColey1]

Foil can be used as a last resort but with it being so crinkly and also so thin the crinkles will bounce light all over the place and not necessarily down. With it being so thin it may burn from the heat of the tubes!!!

Plantedtank.net also had a really interesting thread with some PAR values on spiral compacts. According to the data there is a very significant difference with the bulb positioned vertically or horizontally

That is tobe expected however PAR is measured at one point. If you use an 11W Compact then directly below it will have high PAR. The further away you go the lower the PAR goes. Longer tubes spread the light out more evenly.

That is where LEDs work so well in that you can spread the whole lot out over the whole of the tank rather than be restricted to having all the light in 1 place, namely the length of the tube or in your case directly under each spiral.

However light is light and for the price spirals are good

AC

 

[Mikaila31]

I've used foil for small tanks. You can get Aluminum roll at most home improvement stores. I've found this to work fine for reflecting. Its about as shiny as tinfoil, but thicker. The 6" wide rolls work the best. Then I just bend them to look kinda like my AHsupply reflectors.

 

[SuperColey1]

The mylar sheets are good which is like 1mm thick foil. Many people use these to make their own. For me I don't see the point when cheap reflectors are only £5 ($7.50.) Seems to defeat the object on this which is saving money. With the foil method you do save the reflector money be it £5 or £10. but you then waste half the power you are consuming by only getting half as much light or use double the power you need to achieve what you could have with half the light.

Over a year spending £10 on reflectors will gain you more than £10 of wasted power, so in the long run its a misnomer really

AC

 

[SuperColey1]

Just read this lot again

I should add that the best reflector is white not shiny metal. Ask NASA

Of course not the plastic inserts you get as stock with some tanks as that goes yellowy but some of the best metal reflectors are brished almost white aluminium. I did a crude test on reflectors on teh barrreport and it went like this:

Picture 1 show a highly polished silver reflector on the left and a brushed almost white aluminium one on the right. the left perfectly smooth surface, the right not smooth due to the brushing. The left one looks much more reflective here with no light being shone directly onto it. In fact you can see me with my camer on the left but nothing at all on the right. Make your guess on the better reflector now and you waste your money

This picture shows the same 2 reflectors now with a light shone at them. Not a high power light or you would just see a blank white image here. This is a small 3 x standard LED (not high power just a cheap battery powered pushlight) to show reflection of light rather than reflection of image that you see in the first picture. Make your guess on the better reflector now and you make a better choice than you would've just looking at the reflector's image:

How much better would you say the unpolished almost white surface is? Its so much brighter that the camera has compensated and therefore the background is darker than the polished reflector picture on the left. A huge mount better.

Here is the full thread on the barrreport. If you think I do long posts on here then think again. I have to split some posts into 2 as I use all 10000 characters allowed inthis thread.

It is 6 pages long and I've just re-read it. I had a little smile to myself re-reading it becuase I am on top form here. lol Was nice to remember.

There is aguy who used to work for NASA in this thread later explaining that white is a beter reflector than a mirror but please read the whole thread.. Not only will you be educated but you will chuckle at my rants and those of the OP and of course it is a darned good read where you will see me for the real me enjoy

I dare any of you guys and girls to challenge me on light after reading it

http/www.barrreport.com/showthread.php/5988-LED-Wholesalers-Rig

AC

 

[UNV_Rasta]

Got an instant headache looking at that thread AC!!! lol! my gosh you guys are some serious geniuses

 

[myrtle]

Blimey, I see why it gave you a headache Rasta! Mind you, 9am on a Sunday is a bit early for me to wrap my brain around anything more challenging than making coffee!!

 

[dayzofspeed]

ouch, now i need to get some sleep

 

[JoshuaA]

Also the light that is reflected back down into the tank will be less intense due to the increased travelling distance. You obviously still get more light for your money though.

I would say that is a bit of an overstatement, considering light will keep travelling until it is absorbed by a surface. I.E if you have a strong enough laser 350mw+ in theory on a cloudless night your beam will ultimately end up on the other side of the universe in a few hundred million years time. So in this case I highly doubt our little florescent tube produce light that diminishes in the space of a few cm's.

I agree though, you do utilise more of the light produced than without anything. Just can't tell how much other than "It looks brighter"