PAR for a SPS tank

110galreef

New member
What would be a minimum number and and ideal number to shoot for:
On sand bed in middle of tank and maybe near top for SPS dominate tank so one could grow SPS about anywhere in the tank.

I am swapping around lighting and have a PAR meter to play around with.

Thanks,
 
Well I don't know the min but I think I run close to the min and grow great sps color and growth rate r very good. I run LEDs so my understanding is u have to add 20% to my readings

Top 200
Middle 145-150
Bottom 120

I have 60 different sps corals under this light since all where 1/2 to 1 in frags now have lots of mini colonies and a few nice size colonies.

Hope this helped

Ps I used to run very high par 400w mH over my sps tanks. I'm not new to sps have been growing for about 7 years now. This is the lowest par I have ever run. I do have sps growing nicely at the bottom of the tank. I recently was just talking with a very well known in r area sps keep been in the hobby for 30 years and I asked him what he keeps his par at he said anywhere from 100-200 for sps.
 
if you plan to keep sps on the sand i would have to say no less then 150. 3-400 on top. 200-300 middle. on my tank i have 3-250w 14k hamiltons hung 14" awl. the sandbed is around 200, on the top of my rocks par is around 275-350, but my rocks are fairly low in the tank at 10" below the water.
 
Well I don't know the min but I think I run close to the min and grow great sps color and growth rate r very good. I run LEDs so my understanding is u have to add 20% to my readings

Top 200
Middle 145-150
Bottom 120

I have 60 different sps corals under this light since all where 1/2 to 1 in frags now have lots of mini colonies and a few nice size colonies.

Hope this helped

Ps I used to run very high par 400w mH over my sps tanks. I'm not new to sps have been growing for about 7 years now. This is the lowest par I have ever run. I do have sps growing nicely at the bottom of the tank. I recently was just talking with a very well known in r area sps keep been in the hobby for 30 years and I asked him what he keeps his par at he said anywhere from 100-200 for sps.

Thanks, Wow that is an amazingly little drop in Par from top to bottom....
Do you have narrow optics?

if you plan to keep sps on the sand i would have to say no less then 150. 3-400 on top. 200-300 middle. on my tank i have 3-250w 14k hamiltons hung 14" awl. the sandbed is around 200, on the top of my rocks par is around 275-350, but my rocks are fairly low in the tank at 10" below the water.

Good info. I should be able to test this weekend. Hopefully I have plenty of PAR! want to get stuff growing and filling in.
 
i just added a few sps colonies today. added them off to the right corner for a few days to light acclimate them. par there is 90. i have a 6ft fixture on a 8ft tank. so i have some lower light sand areas on the edges.
 
There is no definitive answer. Many factors play into how much light a coral requires, including water flow, nutrients and light spectrum. Lighting strength is just one factor.
 
Yeah I get that the answer is gonna be vague and depends on what i plan to keep where. JutS just trying to have a gauge. Say I get PAR of 200 on sand bed. I know I'm doing good or whatever. Relative....
 
Top 200
Middle 145-150
Bottom 120

For an LED lighting system, I would say those are very good PAR levels.

For MH I would say:
Top: 300-400 µmol·m²·second
Middle: 180-300 µmol·m²·second
Bottom: 130-180 µmol·m²·second

For T5: around similar to MH; maybe slightly lower due to T5 light covering most of the coral surface.

Have a look at this:
Coral-light-requirements.jpg


The image is from Reefworks.com which is a UK Aquaculture farm.

You can see that generally SPS are quite happy with PAR levels of 150-250 µmol·m²·second.

Have a look at this article by Dana Riddle:
http://www.advancedaquarist.com/2007/3/aafeature1

The above article shows that we dont need crazy PAR levels on our SPS.

Hence I would consider 400 µmol·m²·second to be very high PAR.
 
as far as i can see in my tank ,which is basically 22" deep considering substrate. i am unable with 250w hamilton mh's in a cebu sun light system, to exceed 400 par anywhere in the tank. even at 1" below the water line. granted my tank has 3/8" glass tops but still i would think it would be higher then that. the highest reading i can get 10" down is 275.

i wouldnt think that i would need 400w mh's on a tank with only 22" in depth with the light height at 14," but my readings seem a bit low. i know the cebu sun fixtures have good reflectors. btw. im using hamilton elec ballasts.
 
Update...So i got my apogee sensor, hooked it up to the multimeter and began running some tests.

I have a large footprint tank and am trying to light it as effectivly and effeciently w/ bulbs and watts. 66x 36 x 24.

I have tried a few combos thus far and this is my first test.

Fixture is a Hamilton Cebu sun. I went with this to see if I can get by with just 2 MH's, avoid any spot light, get good spread and still get enuf PAR for an SPS dominate tank. I also use the lumatek select awatt ballast so I can determine or even swap 250 and 400w bulbs. 400w for growth and once filled out cut back to 250's...we will see Heat not really an issue for me. Helps to minimize heaters run!!

New XM20k & 4 t-5 (80w) Blue +, Coral+, purple+ and a 10k...
MH's Bulb 12" from water, glass splash sheild removed, and 400w setting NOT SL

I am seeing PAR of:
~ 850 just under water surface in the center 40" of the tank.
11" down I am seeing about 500 PAR under the bulbs and only dropping off to 250 all the way to the outside edge
Bottom minimums of 200 PAR in the bottom corners and up to 350 PAR peaks with an avg of like 250 PAR most everywhere

Sounds like in general I have pretty good PAR in a large tank w/ a low PAR bulbs

With the 2 MH's alone I seemed to have about:
500's PAR just under water.
250 PAR mid level, ~150 PAR outside 8". Only a few things out there anyway and lower light SPS or LPS or Zoas
125 PAR near the bottom, only 100 PAR outside 6" edges...nothing really there


I have my 1 mos old Hamilton 14k 250w MH's I am going to put in and see how the par is in releation. I know i will get more PAR from the Radium, which maybe next bulb swap. Or go to a 14k MH and use more blue+ t-5 and not the 10k bulb & coral+ (~12k)
 
Last edited:
good results. it looks like your running a 14k setup with your t5's.

i think the 400w are the way to go.. i wish i did. i might upgrade the middle mh on my tank to radium 400.
 
Last edited:
Not necassarily 400w needed, especially since you have 3 bulbs. Why do you have glass tops?

On my frag tank(60x32x12) with a 48" -2 250w HQI & 2 54w(Blue+) T5 Maristar fixture 11" from water, ON HQI setting and 6 mos old Phoenix 14K bulbs:

500PAR just under the water under bulbs, and 310PAR in between bulbs
350PAR under bulbs ~6" deep, and 260PAR in between bulbs
250PAR 11" down(bottom) and like 230PAR in between bulbs ...

MH only:
380PAR just under the water under bulbs, and 175PAR in between bulbs
260PAR under bulbs ~6" deep, and 190PAR in between bulbs
190PAR 11" down(bottom) and like 170PAR in between bulbs ...



I am going to instal my old Cayman sun reflectors on here and see if PAR goes up or down. These are better reflectors, but will have no t-5
 
i thought of removing the tops but i have 2 concerns. the main 1 is fish jumping out. it seems that every time i remove top i end up with a fish on the ground. the second is evaporation. i seem to have much less with tops on.

should i remove the tops? i know i would have higher par #'s for sure.

that maristar is basically the same as the fixture i had on my coral holding tank but mine was 18" deep..i think i had 4-t5's . but same mh bulbs. similar par #'s also.
 
Last edited:
Depending on the iron content of that 3/8" glass, it could potentially be blocking 10-20% of the PAR. I know my 1/4 acrylic top costs me about 7-10% depending on how clean it is, and acrylic is one of the clearest materials.

You could replace the float glass with starphire, that would probably get you 10% more PAR, but probably cost pretty dear. Acrylic warps real bad unless it's braced.

A layer of dust or salt can cost you as much as 50% of your light.
 
i thought of removing the tops but i have 2 concerns. the main 1 is fish jumping out. it seems that every time i remove top i end up with a fish on the ground. the second is evaporation. i seem to have much less with tops on.

should i remove the tops? i know i would have higher par #'s for sure.

that maristar is basically the same as the fixture i had on my coral holding tank but mine was 18" deep..i think i had 4-t5's . but same mh bulbs. similar par #'s also.

Remove tops. If you want les evaporation reduce surface flow a bit.
Do a DIY net screen from BRS if worried about jumpers.



Also I will have to load a pic with PAR numbers!!
 
I was debating it. But I lowered the light some and added1 hour. I will try that first. Par went up about 50 lowering the light 4"

On another note. I'm not sure I like to Hamilton 14k bulbs. They are very white. I should've gone with 400w radiums from the start
 
Back
Top