Herbert T. Kornfeld
In Memoriam
Im going on 18 months with my Aqualine 10,000Ks...they seem to be holding spectrum just fine.
Lighting Website Updates
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FastUno
New member
Sanjay, I know this one may be a tough one to answer, but here it goes.
I am in a situation where I will have a glass shield on a SE MH set & expect to loose some 15-20% of pars. The only advantage I have to combat the loss is that the fixtures will be directly on top of the tank, as opposed to the normal 6-8 inches above the tank that we see. How much more pars do you think are gained by having the MH directly above the tank?
When you perform your plot tests, how far away from the bulb do you normally take your measurements?
I am in a situation where I will have a glass shield on a SE MH set & expect to loose some 15-20% of pars. The only advantage I have to combat the loss is that the fixtures will be directly on top of the tank, as opposed to the normal 6-8 inches above the tank that we see. How much more pars do you think are gained by having the MH directly above the tank?
When you perform your plot tests, how far away from the bulb do you normally take your measurements?
Sanjay
Premium Member
Having your light closer to the water surface will help. How much is hard to quantify, especially since you will be increasing peak values, but also changing the spread. If you still get good spread in the tank, then lowering the lights will definately compensate for the loss due to the glass shield.
For the lamp data, the distance that I have used for all tests is 18". For the reflector data, the measurements were at 6", 9" and 12".
sanjay.
For the lamp data, the distance that I have used for all tests is 18". For the reflector data, the measurements were at 6", 9" and 12".
sanjay.
Travis
10 and over club
FastUno, is the 15-20% loss just a guesstimate? I am just curious because I use a 1/4" glass (regular glass) shield during the summer months to help keep the tank cooler. I searched for a while before I decided on the shield but I never came across any data that showed what the true losses would be with any type of lens.
The Grim Reefer
Ready for some NOBALL!!!
I just measured my actinics with and without the glass top, just a tad over 20% loss.
FastUno
New member
My numbers are from estimates from reports such as Grim's & Sanjay's. For those who have tested with shield, how thick was the glass shield & does the same apply for acrylic? I would think the thickness & the composition of the glass/acrylic should make a difference.
I am sure this adds another layer of complication in terms of quantification. I am also sure that the position of the shield relative to the bulbs also makes a difference in the refraction of light & thus the spectral & par outputs.
Sanjay, your tests are done with the probe exposed to air, or actually in the water?
I am sure this adds another layer of complication in terms of quantification. I am also sure that the position of the shield relative to the bulbs also makes a difference in the refraction of light & thus the spectral & par outputs.
Sanjay, your tests are done with the probe exposed to air, or actually in the water?
Travis
10 and over club
I'm also curious as to what thickness the glass was in the testing.
FastUno, I personally wouldn't recommend using an acrylic shield. That is what I tried initially. People told me it would warp due to the heat from the bulbs but I thought my design would prevent that as I'm exhausting most of the heat outside. Sure enough, the acrylic warped big time in about a month. Of course, it was only 1/8" thick, but I think even 1/4" would warp pretty fast. I'm sure it would allow better light penetration but at a higher cost due to the need to keep replacing it.
Has anyone performed tests with different types of materials such as glass vs. low iron glass vs. acrylic to see what the differences in light penetration are?
FastUno, I personally wouldn't recommend using an acrylic shield. That is what I tried initially. People told me it would warp due to the heat from the bulbs but I thought my design would prevent that as I'm exhausting most of the heat outside. Sure enough, the acrylic warped big time in about a month. Of course, it was only 1/8" thick, but I think even 1/4" would warp pretty fast. I'm sure it would allow better light penetration but at a higher cost due to the need to keep replacing it.
Has anyone performed tests with different types of materials such as glass vs. low iron glass vs. acrylic to see what the differences in light penetration are?
FastUno
New member
I have a T5 setup with an acrylic shield & was wondering how much light I was losing with it on? I also get a slight warp effect at the edges of my fixtures, but nothing major. I could only imagine the effects of acrylic under a MH sys.
Sanjay, have you done any tests with T5's? If so any links or posts?
Sanjay, have you done any tests with T5's? If so any links or posts?
The Grim Reefer
Ready for some NOBALL!!!
Accurate T5 data in the works? Cool!
Herbert T. Kornfeld
In Memoriam
70watt halides, 1000watt halides...whats next? I would be interested in 1000watt halides because things seem to change alot at that level...just like how cheap hamilton 14,000K bulbs have horrible PARs compared to an Aqualine 10,000K at the 250watt level...but best them in the 400watt level. The hamilton 14,000K is half the price of many other 1000watt bulbs...10,000K and 20,000K...I wonder how it does. It seems like the outputs of bulbs at that level change a bit as well...20,000K bulbs seem whiter at 1000watts, 14,000Ks look like 10,000Ks, etc.
The Grim Reefer
Ready for some NOBALL!!!
Hey, I get my arms wet and scare the crap out of my fish when I do readings
No substitute for your precise readings but I guess they do some good. I am sure SLS hates my guts after the reflector readings I posted
No substitute for your precise readings but I guess they do some good. I am sure SLS hates my guts after the reflector readings I posted
RedEyeReef
Active member
The Grim Reefer said:Hey, I get my arms wet and scare the crap out of my fish when I do readings
Do you have a link to this data?
The Grim Reefer
Ready for some NOBALL!!!
It is a thread in the equipment forum in the thread "the great T5 glarathon".
Herbert T. Kornfeld
In Memoriam
Sanjay, 2 Qs...
One, I thought you tested the hamilton 250 - 14,000Ks in the DE version as well...they arent on the site...???
Also, in late Sept, Penn State is having some big meeting on china<<<not sure what exactly yet. My woman was asked to participate (grad student with vast international first hand experience) on one of the panels...so it looks like a visit is in order! It would be an adventure to see what you have going on...up for visitors?
One, I thought you tested the hamilton 250 - 14,000Ks in the DE version as well...they arent on the site...???
Also, in late Sept, Penn State is having some big meeting on china<<<not sure what exactly yet. My woman was asked to participate (grad student with vast international first hand experience) on one of the panels...so it looks like a visit is in order! It would be an adventure to see what you have going on...up for visitors?
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