Par recommendation?

[b4tn]

I got my hands on an apogee par meter and did some initial readings. I have ocean revive lights 12” above and 18” deep tank currently set to 20 white and 85 blue. I was really surprised at how different the intensity was at certain parts of my tank on the meter vs what I thought it would be. But on the sand bed I’m getting 130 and 160 par in the “hot spots” sides are closer to 100. Mid tank (my highest rock work) is 250 range. And top of the water is in the 350 range. I will map it out more when I have some time. My question is how much par do I truly need? I see par maps showing 600 par at top! And 100ish on the bottom but that’s on deeper tanks. If I crank up my lights I could probably get numbers like that but LPS would suffer on the bottom. So do I need more than 250-300 par at mid tank level for SPS? If I go with 25/90 on my lights it puts me right around 400 at water level and but the sand bed is kind of hot getting close to 200. What are good levels to shoot for in a mixed reef?

Not the most recent pic but gives an idea of the layout.

 

[Big G]

I recommend Dana Riddle's MACNA speech on PAR. It's kinda long but worth the watch. The info you are interested in is around 22 minutes into the speech.

https://www.bulkreefsupply.com/vide...light-water-motion-by-dana-riddle-macna-2016/

 

[Biokabe]

As always, the conditions in your tank outweigh whatever outside information you may have read. Don't chase numbers - use numbers to help guide your results.

Do your high-light corals look happy and healthy? Are they growing well? Or do they act starved for light?

If your corals are doing well, I wouldn't worry too much about trying to hit someone else's PAR numbers. If you think they can benefit from more light, increase your settings slowly, and observe how they react. If they respond positively, keep the higher settings. If they don't, then dial them back.

 

[BigRich]

Hi,
I have a mixed reef but more sps. I have 400 PAR on top level of my structure and my sand(hottest spot 150ish, lowest 105). Some sps are beautiful, great growers in that 250 range but others, to reach full color potential, may need 350-400 PAR. So if you like how everything is growing right now I would just shop for sps that do well in that lower PAR area. Also, from what I've been told, measure your PAR with your flow on for the most accurate measurements. I know there is a fair difference in PAR rating with flow on vs flow off, so just a heads up.

You could also "build up" that left side so you can keep the higher required PAR Sps as well. You still have option with your aquascape without turning up your lights.

 

[b4tn]

Thanks, since I only have the par meter for a couple weeks I am trying to set a baseline, get an idea what spots in my tank get the most light, and readjust the frags I have to better locations. Most of my SPS right now is still new little frags so they are in Temp locations. But for instance the acro on the far right has uniform color but you can tell its really reaching to the higher light area. Par tested in its general vicinity was only 150.

I think i am going to shoot for 400 on the surface and 150-200 on the bottom then as mentioned above build up the aquascape a bit on the left.

 

[BigRich]

Thanks, since I only have the par meter for a couple weeks I am trying to set a baseline, get an idea what spots in my tank get the most light, and readjust the frags I have to better locations. Most of my SPS right now is still new little frags so they are in Temp locations. But for instance the acro on the far right has uniform color but you can tell its really reaching to the higher light area. Par tested in its general vicinity was only 150.

I think i am going to shoot for 400 on the surface and 150-200 on the bottom then as mentioned above build up the aquascape a bit on the left.

Sounds like a plan just make your adjustments very slowly. I think I only increase lighting by about 10%(On my radions if overall intensity is at 40% I would only raise 4%) every 2/3weeks. This way I can monitor the corals, ie color/polyp extension. Slow is fast in this hobby lol Really the most PAR a sps needs is 400, maybe 450 for optimal coloring/etc. Usually you can be fine with 300-350 PAR. Also make sure you have lots of flow as you raise PAR. Best of luck! Rich

 

[b4tn]

I recommend Dana Riddle's MACNA speech on PAR. It's kinda long but worth the watch. The info you are interested in is around 22 minutes into the speech.

https://www.bulkreefsupply.com/vide...light-water-motion-by-dana-riddle-macna-2016/

Thanks @Big G, great video. Interesting.

 

[jda]

I would keep them below 350 in the higher parts with coral with that light with 100-150 on the sand bed - any more and you can burn more sensitive corals. You can go up to 750-1000+ with other kinds of light. The type of light matters. The quality of light matters. Try and match up your light with other PAR maps from similar lights.

For example, read about the Emerson Effect where red and far-red (IR) can allow proteins to move energy from photosystem 2 (PSII or PS2) to PS1 to allow more energy to be processed. MH have red and IR. Some T5 do too. LED usually does not - the Orphek Atlantik V4 does for exactly this reason. This phenomena is one of the many theories why corals can take much more PAR from MH or T5 than they can from LED.

 

[MrObscura]

I think people over estimate necessary par values. With proper flow and nutrition I think even most acros will thrive in anything above 150 par. Though mh, and t5 par does seem different than led with leds requiring a lot less.

Hell WWCs 300g gets 250 max par at the surface with some acros in the tank only getting around 100.

As mentioned just use par as a loose guide and observe your corals for actual evidence.

 

[jda]

If anybody has ever seen what high PAR, high quality lights can do on a reef, then you will never want to go back. There is no doubt that not all species need all that much, but I can grow even mushrooms, Z&P and all acropora faster with better color under higher PAR than under lower. Keep in mind that nearly everything that we have in our tanks (with some exceptions) are collected very shallow with one breath and the PAR is very high being 2200-2400 at the surface and still very high down into the water.

These corals get all of that 2200-2400 PAR and still have the energy to overcome being out of the water for parts of the day. Just imagine the alk swings, and other red-herring problems that people encounter that could be overcome if they just had more light to get corals energy like these get:

 

[MrObscura]

Actually shallow water corals don't use as much light as you'd think. Check out Dana Riddles study. They go into photo inhibition very early in the day.

He concluded that the corals he studied, pocillopora in a few inch deep tide pool, got the equivalent of 250 par over 12 hours in a reef tank. And these were some corals get the most light physically possible in the world.

 

[jda]

Only Porites (not Poci) in Hawaii did. He flat out says that the studies were not probably applicable to other corals.

 

[MrObscura]

I'm pretty sure he said that if you can deliver 250 par that should be more than enough for pretty much any coral to thrive. Maybe I'm wrong.

Anyway, in the end I think there are more than enough tanks with acros thriving in lower par to prove that the old belief that they need crazy high par simply isn't an absolute.

 

[Bpb]

Those of you resting the gospel of light levels on the brs video and the ONE Hawaiian porties study by Dana Riddle should take care you’re interpreting the results correctly.

Photoinhibition isn’t the same across the board. Flow and nutrient levels, as well as acclimation periods will shift when photoinhibition occurs on most corals we commonly keep.

The data those studies and videos presented is good, but it’s been grossly misinterpreted. People are now saying “anything over 250 is photoinhibition!! Brs and Dana Riddle said so”. It’s not that simple. That is referring to a very tiny sample base in one part of the world. Dana himself will tell you that many common “sps” corals can acclimate to MUCH higher par levels before reaching photo inhibition

 

[MrObscura]

I'm a noob so I just go on the research I've been able to dig up. Mostly I base my approach on tanks I'm impressed by.

Yes, corals can clearly adapt to crazy high light, but what's the point? Why provide excess light that doesn't accomplish anything? Like I said I'm just a noob going off other people's tanks, but I think there are enough of them proving incredibly high par isn't necessary.

 

[Bpb]

I'm a noob so I just go on the research I've been able to dig up. Mostly I base my approach on tanks I'm impressed by.

Yes, corals can clearly adapt to crazy high light, but what's the point? Why provide excess light that doesn't accomplish anything? Like I said I'm just a noob going off other people's tanks, but I think there are enough of them proving incredibly high par isn't necessary.

Because colors and growth are improved.

 

[MrObscura]

But I'm not sure they are after a certain point. I've seen tanks with "lower par" have just as big and coloful acros as tanks with very high par.

 

[Bpb]

But I'm not sure they are after a certain point. I've seen tanks with "lower par" have just as big and coloful acros as tanks with very high par.

Well there you have answered your question. Run a low par tank if that what you want and let the rest of us just be inefficient and old school

 

[jda]

Dana is available in his forum. He has responded a lot to this. The study is correct, for a few proteins on Porites. Have you ever kept Porites? It is not all that common anymore, but a long time ago, I grew it in my fuge under a 60w incandescent light bulb... it thrived and spawned.

More high quality light does accomplish something. Go check out the old tank of Steve Weast at oregon reefs. Go over to ReefCentral and check out Copps new thread in the SPS forum. Look at the people who grow acorpora from a 1" frag to a basketball in about three years. They don't just light the corals with what is barely necessary. Find the people who don't really want to be found or don't post much - just because they are sick of fighting with noobies and frontrunners, they are still a great source. Big E on here has a great T5 tank with overdriven T5s.

I might suggest that you take the approach that nature is right. It is right about a wide spectrum of light from about 350 to 850nm. It is right about high quality and high quantity. If you give these corals energy that they get in nature, then all of a sudden alk swings, calcium issues, etc. are no longer an issue - nobody ever heard of an alk swing killing a coral until under lighting them with blue LED was a thing.

Nobody said that more light was necessary to all corals... only that if you do provide more high quality light, that growth will increase and usually true color will too (not the black-light RB diode look, but true color). They will also be more hardy. What corals people are keeping matters a lot. For me, I do not want to just "just enough" for my corals. I want to give them as high quality of an environment as possible and I have seen the results of doing so. If some alien came and abducted one of us, you would want the same thing and hope that the aliens were not arguing over what is absolutely necessary and what is not.

Your opinion of what impresses you will change over the next year or two. All of ours did. If you have a penchant for details and achieving the highest level, you will gravitate towards higher quality and quantity lit tanks. In time, you will start to see the differences that you cannot see now.

 

[MrObscura]

I thinks there's a difference between not enough, the right amount, and excess.

It does seem that par isn't always equal in regards to MHs and T5s vs LEDs. Also photo period length and spectrum play a role.

While I'm sure I'll learn a lot more as time goes on, I'm not sure my idea of impressive will change. Thriving colorful corals are thriving colorful corals.

But I'm not trying to convince anyone to change their ways, you've all been doing this far longer than I have, or do things my way, just having a friendly convo.