Thoughts on new halide setup (par levels)

Velcro · Sep 21, 2018

I just switched from all LED to halide to see if I notice any difference better or worse with the old vs new tech.

This tank is 36x36x25. I have attached a picture with par readings. This is with the older style apogee sensor and no immersion factor considered. This is a cozumel 20x20 reflector with a radium 20K bulb and an icecap electronic ballast running the 400W superlumen setting.

The 250 level is roughly the centerpoint of the tank while the lower par levels are the first 25% or so of the width of the tank.

Obviously this is an acropora dominant tank and I wasn't planning on adding any more LEDs other than a couple of reefbrites, but I'm concerned about the par levels.

Please ignore the ugly rig right now... temporary until I figure out what I'm going to do with mounting.

chipmunkofdoom2 · Sep 21, 2018

I think these PAR levels look okay. The output from a MH bulb is going to be very even and well distributed. The PAR might look a little low, but it's going to be very well-distributed and there will be very few dark spots.

Maybe someone with some more halide experience can chime in. But they look okay to me.

Crabs McJones · Sep 21, 2018

How long after the bulb came on did you take these readings? From what I was told, you want to wait at least a half hour before taking par readings.

Velcro · Sep 21, 2018

Crabs Mcjones said:
How long after the bulb came on did you take these readings? From what I was told, you want to wait at least a half hour before taking par readings.

been a couple hours

jda · Sep 21, 2018

Do you have the glass on the Hamilton? You can get more output if you take it off.

You do need to consider the immersion factor... you have 32% more PAR than you are reading with an older Apogee. Take the output times 1.32 and you have 330 PAR in the middle. Then, consider that the MH has wavelengths that the PAR meter cannot capture at all or very well (UV, IR and most output under 440nm) and you can figure that you have even more PAR. I think that you are OK.

mcarroll · Sep 21, 2018

I like it.

mcarroll · Sep 21, 2018

What were levels previously?

Velcro · Sep 21, 2018

mcarroll said:
What were levels previously?

I think I had the LEDs at about 50par higher in all those spots

KrisReef · Sep 21, 2018

(What's par? I want your clam. )
Has the clam changed how it's holding its mantle since you switched the lights? I would think that if it was getting less light that it might open more. The way it is sitting in the photo, it looks happy -as- a- clam.

Velcro · Sep 21, 2018

KrisReef said:
(What's par? I want your clam. )
Has the clam changed how it's holding its mantle since you switched the lights? I would think that if it was getting less light that it might open more. The way it is sitting in the photo, it looks happy -as- a- clam.

I've only had the halide a day

KrisReef · Sep 21, 2018

Oh, well that is not very long. Give us an update(s) over the next week.
& If that clam starts to suffer, I'll hold him for you.

jda · Sep 22, 2018

Also, a 36x36 tank is no joke to light. You probably know this very well by now.

You probably have more light now than you did. Remember that the old Apogee over samples light in the middle of the visible spectrum, which LED mostly are... and it under samples the MH. This is a guessing game, but I would guess that you are at least the same with a slight lean to having more.

Velcro · Sep 22, 2018

jda said:
Also, a 36x36 tank is no joke to light. You probably know this very well by now.

You probably have more light now than you did. Remember that the old Apogee over samples light in the middle of the visible spectrum, which LED mostly are... and it under samples the MH. This is a guessing game, but I would guess that you are at least the same with a slight lean to having more.

Lets hope so. I'm still very impressed with this single reflector and the PAR it produces. Like i said, I'll be adding either T5 or LED, but don't have room for both. This isn't so much for spectrum, but just for my visual take on the tank. It will probably be reefbrite XHOs. I just don't know how I'm going to mount them. At this point I think I'm going to be making a floating aluminum angle frame to place the reflector on and hang from the ceiling. I'll make it the full 36x36 so I can kinda mount whatever on it.

Velcro · Sep 23, 2018

jda said:
Do you have the glass on the Hamilton? You can get more output if you take it off.

You do need to consider the immersion factor... you have 32% more PAR than you are reading with an older Apogee. Take the output times 1.32 and you have 330 PAR in the middle. Then, consider that the MH has wavelengths that the PAR meter cannot capture at all or very well (UV, IR and most output under 440nm) and you can figure that you have even more PAR. I think that you are OK.

I read on apogee's website that the immersion factor for my sensor is only 1.08 btw.

Velcro · Sep 27, 2018

One week in. Everything seems fine, maybe a loss of some color here and there. I started at 4 hours a day photoperiod and increased by 30min every day. I'm now at 7 hour photoperiod and will probably keep it there until I add some T5 or LED.

jda · Sep 28, 2018

Once they start to respond, you can take this up to 10-11 hours and they will respond even further. You probably do not have to, but I notice better color and growth with 10-11 hours of light from my Halides.

Velcro · Sep 28, 2018

jda said:
Once they start to respond, you can take this up to 10-11 hours and they will respond even further. You probably do not have to, but I notice better color and growth with 10-11 hours of light from my Halides.

Yea I think I'm definitely going to have to increase photoperiod due to lower par. It will be a while until I have any supplementation on here.

jda · Sep 28, 2018

Did you keep the glass on there, or take it off? If you need more PAR, consider taking it off, if you have not already. People are somewhat mixed on this, but not too many use glass on 20k Radium.

Breadman03 · Sep 28, 2018

See how the light is shining on your rig along the tank trim? Note the strong illumination that cuts off maybe 2-3" above your water line. Assuming everything in level and square, you could drop the halide until that cutoff is at your water level for maximun PAR and minimizing light spillage. I don't know how much it would increase it by, but it might be a few percent.

Velcro · Sep 28, 2018

jda said:
Did you keep the glass on there, or take it off? If you need more PAR, consider taking it off, if you have not already. People are somewhat mixed on this, but not too many use glass on 20k Radium.

I didn't remove it. I get a lot of splashing and already have some on the outside of the glass so I'm trying to keep the reflector in good shape