[ben]

this was posted on another forum and i thought it was worth posting on here.

Just got an Aquaray reef white, its 7:30am with no lights at all on the tank, the unit is sitting 4” off the water and here what I got with my meter!

Just under the surface around 180 par
7” under the water 80 par
12” under the water 40 par
30” under the water 15 par

Ok I know it’s 400w against 12w but here’s what I got with my halide
Just under the surface 1300 par
7" under the water 500 par
12” under the water 250 par
30” under the water 150 par

Just to pint out if you add another led light you don’t double you’re reading, i.e. 80 par will not become 160 par, there will be an increase but not a lot! I’m not going to spend the money to find out lol!

OK, I can see the light on no problem, it does shine down on the sand, but when I tried it with the halides on I could hardly see any difference, not even the shimmer effect was anything to write about!

The lights maybe good for shallow tanks? And also for fish only I would look at it, I only tried the reef white and the marine white looks brighter?
This is not to prove anything but to give some information to anyone who is looking into them!
The readings are approx as they do change with every bit of movement!
Meter is new ish and is a quantum opogee.

This was a guide given:
Low light - mushrooms, zoanthids & most soft corals - 50-150 PAR
Medium Light - LPS, Clams & some SPS - 200-300 PAR
High Light - Acropora, Montipora and some SPS - 400-600 PAR
Very high light - Some SPS - 700-1000 PAR



Thanks
Glen


thanks glen for letting me post this

[Tony B]

Superb information - looks like halides will be here for a good few years!

[Tiggs]

Just to provide an alternative view (but with less science!) I have aqua rays over my 32" deep tank and LOVE them! I had twin 400w halides before and these are a huge improvement IN THE AREAS I NEED.

The light is better spread over the tank and "crisper" .... hard to explain but the tank is less bright but sharper. It's like having your TV set up properly....suddenly you realised that what you thought looked good before was actually not that good at all.

The light doesn't spill into the room so the tank fits into the living space far less intrusively. There is little or no heat put into the water so i am running at 26 with ease as opposed to hitting 29/30 with fans all over.

The blue LED's can't be beat by ANYTHING for night time glow and shimmer....superb.

And they take up less space over the tank so my wood cladding will be far easier for me (my carpenter) to fit with no ugly lights hanging over the tank.

Stock wise...i have softs, LPS, BTA all doing great...growing and responding to the light perfectly. I have also left some SPS and a giga nem in to see how they do...so far they are fine.

For me and my objectives these are great.....couldn't be happier

[ben]

could we see some pics please tiggs

[Tiggs]

at some point - i'm making lots of changes to my system so i'll do a photo update at some stage.

[ben]

more from glen

A = Just under the surface
B = 7” under the water
C = 12” under the water
D = 30” under the water

........400w....../ 250w..../ LED reef white.
A = 1500 par / 800 par / 180 par
B = 500 par / 350 par / 70 par
C = 250 par / 160 par / 40 par
D = 150 par / 115 par / 15 par

Just checked the 250w and got this:

Just under the surface around 800 par
7” under the water 350 par
12” under the water 160 par
30” under the water 115 par

The 250w lamps I tested were Arcadia lamps, I should have my delivery of cheap lamps so I will replace them when I get home and also test them just to see if there is any difference, the readings are a guide as movement in the water makes it’s very hard to get a 100% reading, also when putting the sensor in the water I can’t get it 100% directly under the lamp i.e. on the sand the rocks do come out more than the lamp (most tanks would) but it’s great to use it right next to where the coral is going just to see the reading you get, which I suppose is better than have readings of a tank with nothing in just to get it under the lamp!
Check out the pic just to show the reading I got, just makes it a bit easier to see!



It just makes it a lot better knowing your tank readings to where the corals will go!

Thanks again, I hope this helps you as it's not to put any Led's down as I would also like to move over to them!

Glen

[matt h]

amazing difference in 7"- 12 " depth ,defo means you need to raise corals slowly to avoid shock..

[Twistedpro]

i dont know, but i find it hard to belive a 400w light was giving out 1500par even a 400w 10k xm bulb only gives out 220

[Simon Garratt]

Taking it that these are 10K's Im a little surprised at that as well as you normally get a marked reduction just under the surface due to reflection off the surface. I tested Si's 3 month old BLV10k's the other day at the surface with what looked around 12" of clearence and got a reading of approx 1200 PPF.

Pete, dont forget that Sanjay's lamp comparisons are taken at 18" from the light source, so the photon spread and capture will be massively different if readings are taken closer to the light source, plus we dont know here what the efficiency of the refector is. Sanjay's data is designed as a way of 'comparing' differing equipment combos, rather than a defiinative guide as to what a 10, 12, 15, 20 lamp will kick out as a deffinate...to truly compare, you have to re-enact sanjays method whichisnt whats happening here.

The other thing to bare in mind is that you have to compensate for differing light sources with a Par meter, ie you have to add 8% if your measuring daylight compared to a MH....

As far as i know most commonly available PAR meters are at this stage not desighned for measuring LED's so the reading 'may' be a bit squewd.


Regards

Si.