par in a sps dominated tank

[uk jon]

Hi guys I've just purchased a ghl t5 hybrid to add to my 5 radion pros on my 6x2x2 ft reef tank.
Heres my dilemma, i have took par readings at various points on my tank/radion at 100% and....
Top 600 par ,
middle 350 ,
bottom 170.
i was thinking i needed more light spread but now I'm worried i will blow my tank away with these now
any tips

 

[Justfebreezeit]

Reduce your radion intensity

 

[jda]

Your acropora can handle a lot of PAR from the T5s... moreso than the LED. I keep some coral well over 600, but they are under MH.

I would not go much above 350-400 with Radions, but with theT5s, I would not sweat 600. If you are really worried, then do what is suggested above and just turn the radions down and let the T5s handle some of the heavy lifting.

In general, the source matters for intensity (PPFD/PAR). A MH or T5 tank can usually pump up the PAR and stuff thrives - the same levels from LED will burn corals and possibly even kill them. The short reason is that the quality is better with the MH/T5, but nobody really knows why outside of some guesses like the LED have rough peaks that are way too high and are smoothed out in Manufacturer charts.

 

[Epic Aquaculture]

I run my Radions at 100% on a modified 18K program with my T-5's I get over 700 PAR at the top, and have corals thriving at that level. The LED's do require slow ramp up and acclimation at that level, but you won't be too strong if you take your time acclimating the corals to it.

 

[uk jon]

Thanks for the replies going to get this up in the next few days.Im Wanting better growth that is my reason for adding the t5s I've only ever used Radion leds so have no experience in t5 or mh. Get ok growth already and dont to really want to upset anything to bad.

 

[hart24601]

I don't subscribe to the unknown quality of light from LEDs school of thought. In my signature you can see the acro I won the growout contest with under all LED and the intensity was 500 PAR with all LEDs. I like the 300-400 par range for acro with LEDs but have run more than that before too. Right now in my 34g nano I have clams on the bottom getting over 400 PAR led only (it's only 12" deep) so some of the acros must be getting just hammered with PAR that are higher up, but no real issues with bleaching on those. I will take a measurement later.

Just keep in mind more light means need more flow all else being equal. Corals dissipate a lot of extra energy via heat, we always see conversations about too much par and bleaching but rarely is there a conversation about flow. You can have a whole lot of PAR if you have a whole lot of flow.

 

[uk jon]

I don't subscribe to the unknown quality of light from LEDs school of thought. In my signature you can see the acro I won the growout contest with under all LED and the intensity was 500 PAR with all LEDs. I like the 300-400 par range for acro with LEDs but have run more than that before too. Right now in my 34g nano I have clams on the bottom getting over 400 PAR led only (it's only 12" deep) so some of the acros must be getting just hammered with PAR that are higher up, but no real issues with bleaching on those. I will take a measurement later.

Just keep in mind more light means need more flow all else being equal. Corals dissipate a lot of extra energy via heat, we always see conversations about too much par and bleaching but rarely is there a conversation about flow. You can have a whole lot of PAR if you have a whole lot of flow.

thank you for you advice its really helpful. I have acros/tenius at 600 par that seem to be doing ok and some at 450 doing a lot better so your advice makes sense