Too Much PAR? A few of my corals seem to think so...let's find out!

In this video, I test the par of my Giesemann Spectra metal halide/t5 light fixture currently hanging over my Red Sea Reefer G2 350.

[@queencityreefs]

Great episode bud. Definitely enjoyed this one. 👌💯✌️

[@Messier87_M87]

One of the nice aspects to MH lights, is that there’s no fiddling with spectrum or intensity. When I got started in the hobby back in the early 2000’s, I used three, 400w MH lights on a 6ft tank. They were awesome, but I had major issues with heat. I hope everything works out for you, that’s a great setup for acropora.

[@zburnreefing]

Luckily the tank is in a basement where it’s cooler, so heat hasn’t been too bad. Just a fan and an evaporative cooling does the trick. The one thing that surprised me (and reminded me) is how well MH penetrates the water. There is very little drop off in par from top to bottom of tank. Causes a little stress with LPS but hopefully it will work out.

[@Messier87_M87]

@@zburnreefing Yea, my old tank was upstairs in my house, so it was bad planning on my part. I’ve totally forgotten what MH look like on a tank. I also enjoyed the comment above from Alex, he’s a really passionate guy, and he is very knowledgeable when it comes to corals. Great video, thanks for sharing your tank. All I watch on KZbin is reef related content, so I really appreciate quality content like yours.

[@jackson6745]

Love the setup, especially the lighting. I am running the 72" Spectra over my current reef with 250w radiums on m80 with added reefbrites. I am getting 800 par at the very top of my rocks, 300ish on bottom. I've been running a halide spectra (250+400) over my last several reefs and get similar par numbers. I will tell you with certainty that your par is not the issue. Without knowing your water parameters I would saw it's likely a lack of nutrient in water, specifically po4. What po4 level are you running? Could also be a combination of not acclimating certain pieces that may have been zoox limited when you got them , possibly in conjunction with a higher than should be alk? I saw your recent growth video, with the right nutrient level dialed in as your tank ages, you can expect that level of growth in 45 days. You have the holy grail of lighting!

[@zburnreefing]

Thanks for sharing your expertise! Yes, it ended up not being the lighting but in fact a lack of nutrients as you described. The lack of nutrients was further exacerbated when attempting to bring on kalk as well. I have since increased p04 to nearly .1 and everything rebounded...but now I am dealing with some algae...need to up the CUC I think. It is hard getting that balance with a tank this young, but hopefully with time everything will come into harmony.

[@76honda76]

Is that a dehumidifier on the left ? Clean setup, how’s the heat that t5 pumping out so far ?

[@zburnreefing]

Hey there, yes that is a dehumidifier. It only really runs in the spring. The tank is in a basement so want to keep the space moderately dry down there. The t5s do put out some heat, but most the heat comes from the metal halides. I have the fan on the side set up to kick on if it gets too warm. However, the fan only kicks on during the summer months. The basement seems to be cool enough that the lights just reduce how long my heater runs. Thanks for checking out the video!

[@dustinseeker5963]

What are some corals you find look good under the old school lighting? I'm running a 6 bulb sunpower and need some suggestions. As you know not all corals look as good under different lighting types. I currently have a few like the Oregon Blue Tort, Tyree Blue Matrix, Tyree Red Dragon, ORA Pearlberry, PC Rainbow, And Purple Slimer.

[@zburnreefing]

Love the ATI sunpower. I think you go for corals with true pinks, reds, and blues. You’ve got some great ones already. Pink stylo/birdsnest, red planet, Hawkins, purple monster, anything from ORA, pink lemonade, garf bonsai, palmers blue milli, sunset milli…ahhh the list goes on. I love the old school sps. What’s your bulb combo? 50/50 blue plus and coral plus? Can’t go wrong with that. Also good to experiment with a true actinic and purple plus as well. Can also save up and throw on a reef brite led strip and you have one of the best lights out there.

[@fletcherwright7042]

Sweet 👍 everything should be good

[@Alex_Correa]

Forget about PAR using the Giesemann Spectra!!!!! The transition from LEDs needs to be slow, but not so critical. Again, you totally wasted your money with that PAR meter!!! For the people that want to try halides... put the halides on for like 2 o 3 hours a day and increase 1 hours every 4 - 5 days to start, up to like 5 hours a day total in the end. The T5s can be on for 8 to 9 hours day max. FORGET the PAR!! That's for LED users!! Your corals look great! You can keep the fixture at 11 inches, no poblem. Change the fan to blow parallel to the water surface. If you had searched on Reef2Reef you would get the info and not wasted money with that PAR meter! Lot's of people going to metal halides and T5s. You have one of the best fixtures in existence!! Good investment!!!!!!!!! Your corals will love you forever!!! Don't worry... everything is be great!

[@zburnreefing]

Thanks for your feedback, Alex! It’s not everyday a lighting expert in our hobby chimes in and posts a comment for one of my videos. I hope to use the Spectra for many years…or as long as I can find metal halide bulbs.

[@Alex_Correa]

@@zburnreefing I'm so happy for you! 👍