Does PAR >250 produce faster growth from sps?

[koral_lover]

It seems many folks around here have mentioned if your sps coral is getting 250 par, it likely will thrive. So does it help to push beyond 250? In other words, if a milli is getting 250 in my tank (and I like the color), does it make sense to move it higher up in the tank to where it could get 450 PAR - will growth speed be faster at a PAR of 450?

Mostly curious how much PAR matters once a baseline of at least 250 is reached. I know every coral has different demands, but in general does more par = more growth even after a threshold of 250 is met?

I want to exclude color from this conversation at the moment, as it appears to be common experience that PAR amounts, even greater than 250 will manipulate color - was more curious about growth.

Thanks all.

 

[ksicard]

I'm no expert by any means but my guess would be that once you hit about 250 growth will more so be determined by water parameters and flow. I think lighting intensity would come in third behind water quality and flow as long as there getting at least 250 par.

 

[DiscusHeckel]

Yes and no.

It all depends on the spectrum. PUR (photosynthetically Usable Radiation) is more important than PAR. For example, you can use T5 tubes heavy on the green and red end of the spectrum and measure 300 PAR. Then you can use different T5 tubes heavy on the blue end of the spectrum (e.g. 453 nm) and measure 300 PAR. Guess which one grows corals better?

Answer: The latter

I hope this helps.

 

[reefwiser]

There was a good talk by Dana Riddle at this past MACNA on PAR and growth.
He found in his study that once you go over a thresh hold of 200 par the coral can stop its growth cycle during the coarse of a day. Hopefully it will be up on BRStv youtube page soon. I good steady even light across your tank is better than blasting sps. More is not always better.

 

[koral_lover]

Thanks all - This is helpful information. I will be on the lookout for the Dana Riddle talk. This confirms that if my PAR is at least 250 with majority of blue tubes and my growth appears slow, to focus on water quality and flow.

 

[Potatohead]

I bought into the hype that SPS needed really high light, and now I am dealing with a tank half full of burned coral... It sucks. I am using anecdotal experience but I would tend to agree an even spread is better, and it likely why T5's work so well.

 

[myaerica]

The Dana riddle talk was great. The main focus was Sps can have too much light and higher alk grows Sps quicker.

 

[Spslvr]

The Dana riddle talk was great. The main focus was Sps can have too much light and higher alk grows Sps quicker.

I believe its higher ph rather than kh that accelerates growth...