Aquarium Lighting With Leds & Fluorescents

[spamalamadingdong]

HI

I have a question regarding aquarium lighting. I have been reading around & getting a little confused
I'm just setting up a new tank thats 48"x12"x15" (38 US Gallons) and it will be planted

I know the rough rule of thumb is the Watts per Gallon rule & the plants I'm looking at using will all be around the medium lighting range ie 2-3 wpg. (so 76w+)

Now does this apply to T8 or T5 tubes? If this is applied to T8 tubes does this just mean that with a T5 tube it'll just be more usable light so basically the efficiency of the light source to convert power into light is much greater than a t8 tube so I will be able to grow higher light plants, basically an extra say 15-20%

Also I'm looking at something like this in conduction with them
http/www.aquafx.co.uk/FX500-IN-STOCK-ORDER-NOW-AquaFX-LED-Lighting-System

Basically I want it so that in the morning I can fade the LEDs up then time the fluorescents to switch on so as I get a smooth transition then in the evening do the opposite and fade down to a moonlight glow for a few hours in the evening then switch off for the night.

So if I use this in conduction with the fluorescents this gives off 15w per tube but this is LED so how does this compare to fluorescents?

I was thinking either
1x54w T5 (46")
2x15w LEDs (18")
or
2x39w T5s (34")
1x15w LED (18")

Would this work? Will the 39w tubes be long enough for a 48" aquarium
Also the tank has glass sliding condensation covers so will this affect any of the light?
Sorry if this is a bit of a ramble but I'm just trying to work it all out


Cheers
Andy

 

[KittyKat]

Firstly, you are better off going for 2 wpg as it is quite difficult to maintain good growth at brighter lighting because you will need to use more CO[sub]2[/sub] and fertilisers, while also trimming the plants more often.

Secondly, it makes no difference, choose whichever you prefer. Wpg is watt per (US) gallon regardless of what it is coming out of.

As for the length of tubes.. that is up to you.. for example, if you plan to have a "mountain" of plants in the centre with no plants on the side, then yeah, shorter bulb could work well! (I have never tried that myself.) On the other hand, if you want even plants along the whole tank, then a longer bulb would probably be best.

 

[SuperColey1]

Forget highlight plants and low light plants. many people grow supposed higlight plants under low light conditions with no problems. I am undure what is the key but I suspect that these 'highlight' plants are actually high CO2 plants.

Highlight users always inject CO2. they have little choice unless they are trying to grow algae yet they never take into account the increase in nutrients. Just that they put highlight there.

Also forget the 2-3WPG. It isn't T5 and it isn't T8. It is T12 and worked out in the 70s/80s to boot. Even T12 technology has moved on since then.

2WPG is enough for everything. Then if you have problems with plants do not assume it is the light. Address the ferts and CO2. That will be most likely where the failure is coming from.

high power LEDs will produce circa...double the output light (not lumens we are talking light) of flourescent lighting. The unit you are linking to isn't going to have any effect on your WPG. From what I can see it is standard LEDs which will not be giving anything in terms of 'real light' It is just for effect.

AC

 

[spamalamadingdong]

Thanks for the replies. I think I'm starting to understand
Thinking a bit more do I really need to go for T5, T8's will probably be more than adequate as the tank is only 15" deep
Just one thing though

From what I can see it is standard LEDs which will not be giving anything in terms of 'real light' It is just for effect.

I have looked on the site and this is what I could find here

AquaFX has been specifically designed to be comparable to the light output of T8 fluorescent and gives much the same light brightness (LUX) but with less harmful UV. LED lighting has a life typically 10x that of fluorescent.

And also here

PAR (Photosynthetic available light) for plant growth is comparable with fluorescent lamps.

So does that mean that they will have some affect?

I'm aiming for an iwagumi style tank probably using riccia as the main base & hope to avoid using a C02 system for now if it can be avoided.


Thanks again for your replies
Cheers
Andy

 

[SuperColey1]

Thanks for the replies. I think I'm starting to understand
Thinking a bit more do I really need to go for T5, T8's will probably be more than adequate as the tank is only 15" deep
Just one thing though

The 'generalised' statement we would give normally is that for all tanks 2ft deep or under that 2 T8 lights that are the full length of the tank is good enough to grow virtually anything you want.

I'll not 'tear' their marketing blurb apart but......well I will tear it apart actually. May as well....nothing else to do:

THE FIRST LINK

AquaFX has been specifically designed to be comparable to the light output of T8 fluorescent and gives much the same light brightness (LUX)but with less harmful UV . LED lighting has a life typically 10x that of fluorescent.
Why have they 'specifically designed it to be comparable to T8 lighting'? LEDs are much better than T8s so why design it to be less efficient than it could be. (Keep that UV statement in mind for later down this post. Lifetime 10x. ha, ha. Try 2-3x. They are using one myth on T8 deterioration time to get the T8 life shorter and then ignoring the deterioration time for LEDs. Classic marketing tactic.

PAR (Photosynthetic available light) for plant growth is comparable with fluorescent lamps.
LED should be way more PAR W for W!!! however if for example they are actually comparing a 15W LED unit to a 30W T8 then comparable is not the word they should be using!!! By using the word comparable we have to assume they are comparing their 15W LED unit to a 15W T8.

Tests show that the PUR (photosynthetic usable radiation) from LEDS is comparable to fluorescent; plant and coral life appear to thrive under LED lighting
Comparable. why are they using the word comparable. LED should be much higher in PAR and much much higher in PUR

AquaFX uses LED technology to ensure that energy consumption is kept to a minimum. Typically in 100% white-mode, the energy consumption is comparable to that of a fluorescent system of the same brightness. Owing to the innovative timer and dimming functions it will draw less power than other lighting.
Again the comparable statement. LEDs should not only give you more light and therefore mean they are much more efficient in that to achieve the same level of light output you use less watts of LED.

Then the last part of the statement is hilarious. LEDs give less Lumens per W than fluorescent. This is confusing to most folks who therefore assume it is less light however Lumens is brightness and not light. LEDs are less bright but have much higher actual light output.
Therefore the energy consumption cannot be comparable to a fluorescent light of the same brightness. You will need more W of LED to get the same lumens (brightness) as a fluorescent however you will need less W of LED to get the same PAR!!!. We aren't interested in lumens unless you want to have the aesthetics of a bright or dull tank. Laughable that one


THE SECOND LINK

LEDS do not create any harmful UV light.
Yes they do but far less than other forms of lighting. They need to make their minds up. In their very first statement if you remember (scroll up) they said 'but with less harmful UV'. Is it less UV or none?

Heat output from the LED tubes is minimal
This could be a good statement or a bad statement as they haven't clarified what they mean.

Good LED setups direct heat away from the fish tank in the same way as PCs direct heat away from the processor. They use heatsinks to draw the intense heat from the LED with just as PCs uses heatsinks to draw the heat away from the processor.

This means there is minimal heat output downward that will affect the water., however there is most definitely heat output from the LED. Do not touch the LED while it is on. your skin will melt to it!!! Hotter than a fluorescent tube to the touch however the overall heat over the are of the tube will be less.

We can run with theie statement here as I assume they do mean heat altering the water temperature below.

White light output has a CRI (Colour rendering index) of 80
All this means is their LEDs have a colour temperature of 8000K. Thats a greenish to gentle blue hue. Most of us making our own LED setups are using daylight 5500-6500K which gives no colouration at all.

So does that mean that they will have some affect?

Hard to say. I would guess so but all the marketing blah above doesn't leave me assured on anything.

Did they test their own unit? A lot of 'comparable with' statements which means either they've designed the units badly, or tested them badly, or not tested them, or just do not know what they are on about and therefore have written their blurb without any relevant info on it!!!

These look similar to the new Arcadia tubes to me which are direct replacements for T8s in that they will fit existing T8 units. The Arcadias (last time I looked) have no tech detail either and they look like rows of standard LEDs and not high output ones. Needs someone in the know with a PAR meter to test these sort of things really.

We know high power LED units are way more efficient than fluorescent (circa 2-3x) and even more efficient than MH (3-4x) but as yet I have not seen any tests done on these tube like setups that use standard LEDs.

They look a little like a try and sell something for the sake of it to me.

I'm aiming for an iwagumi style tank probably using riccia as the main base & hope to avoid using a C02 system for now if it can be avoided.

Riccia likes CO2. Works well floating where it has ample CO2 or on the substrate with CO2 but can be pretty hard without!

As per first statement 2 x T8 full length tubes will get you the iwagumi you want. Pressurised CO2 would be preferable for a carpet though

AC

 

[spamalamadingdong]

Thanks SuperColey1 for such an in-depth answer, thats extremely helpful!

Ideally the LED was more for the fading up of lights and an evening glow. I did start to look into the Arduino as a controller but got out of my depth
So thinking about it I may avoid this setup for now and just go with the standard tubes and maybe add a simple LED setup just for the evening along the lines of this

I was reading up more about various plants last night and especially riccia and realising I may have to use C02
I've had a brief look through c02 systems, but I think that's my homework for this week to look into C02 more & work out what kind of system I can build/buy that will work well with my setup!

Thanks again for all your help it's been invaluable


Cheers
Andy

 

[SuperColey1]

Don't get me wrong. That unit may be fine. It is the marketing blarb that is questionable. However £120 for a 15W light?

I guess if you are happy to spend that then you could get that unit and then use 2 x 4ft T8s either side of it.

I'm sure it will do the job of the sunrise/sunset nicely and probably provide some real light on its own, however you won't be able to fade the T8s.

That meas you'l go slowly from nothing to 15W but then each T8 would still increase from nothing to full. lol

There is someone I know that has programmed a little circuit board for hs setup which fades both the LEDs (proper ones) and T5s in. That requires dimmable ballasts for the fuorescents though and dimmable ballasts can be expensive.

AC