Lets talk about lighting an SPS tank

[dgasmd]

Very interesting observations. I haven't played with many lights yet, but my observations ahve been pretty consistant with most.

Had a 125g tank with 3x160 watt atinics and 3x160 watt aquasuns. Colors were outstanding, but the entire tank was frags and the growth was lacking. However, there were a couple of corals there that came in larger size and those tend to grow faster than the frags under the same VHO.

Went up in tank size to a 360g tank and used 4x400 watt radiums on eballast. Color visually was outstanding, although close not as good as the VHO. Growth rate was considerably better though. Also, found out radiums are pretty much gone down to 40-50% visualy, so I can only imagine the PAR, at the 5 month mark. Went to Ushio 10,000K and the growth exploded as if I had flicked a switch. The color in some corals was exactly the same as before if not more intense. Some others did not look as vivid though.

Another observation was the bulb distance to te water surface. When I started with the radiums, they were about 6-8" above the surface. After a month or so, I dropped them to about 3-4" from the water. Very significant difference.

My plans for the next tank are a combination of 3 XM 10,000K alternated with 2 radiums all on blueline ballast. I am also using lumenarc 3 reflectors, which should make a huge difference. I am also adding 4x48" and 4x36" VHO actinics to it all. My plans are to run the VHO for 14 hours/day and the halides for 8 hours/day.

Joe:

Which reader do you recommend of those in the link? Calibration really needed or not? remote sensor is better to read under water right?

 

[Wilafur]

2 Bulbs Correct? What ballasts are you using? Off topic Wil, but does that Willi Milli like lower light?

yes two bulbs total. both are run off IC e-ballasts.

the willi milli LOVES light.

 

[coralite]

dgasmd, if you are considering a quantum sensor to use in your tank then you will definitely want to consider a unit with a remote sensor assembly. Also, the external sensors I am used to are either for submerged or emerged applications, or they must be "configured" for one or the other. Mine is configurable for both and I cant see going any other way with it.

 

[skeets]

Apogee Instruments QMSS-ELEC Quantum meter with sensor. Calibrated for electric lamps

Is this a sensor that can be dropped into the tank to actually check out par levels where my colonies are? Or is this a above surface par lvl meter?
If its not a underwater one, do you know of one?
It looks really cool... pricey, but to me it would be worth it. I dont know a whole lot about what values are good, and how to use one etc. I see you say between 200-400 is good and some places on the reef get a 600.

Also this will work on the adequate light spectrum levels right? It talks about over/underestimating and such. I havent had a chance yet to sit down and look at what spectrum my bulbs are high in etc.
Thanks for the help guys...

 

[JB NY]

Buy the one I link to QMSS-ELEC Quantum meter with sensor. Calibrated for electric lamps. When calibrated, the meter is good to within 5% of the Li-Cor sensor which is about 5x the price. The sensor is submergible so it can be used for in tank readings as well.

It seems like an expensive purchase but compared to the amount of money we spend on SPS colonies and lighting, it's really not that bad.

 

[dgasmd]

You know, I think I am going to bite the bullet and do this right. At least I will be able to tell what I am getting out of my bulbs, not to mention that it will give me the best indicator of when I need to change them. That brings up another question: what drop (percentage) in PAR is considered acceptable over time before you go and get a new bulb? That would really be what tells you when the bulb needs changing.

 

[coralite]

I wouldnt be so concerned with a specific drop in ppfd values. If your bulb is still throwing out sufficient irradiance then there is no need to change them. I think if you're getting 300+ umol in the top half of your tank then you will be set for a mostly sps tank. Now due to spectral shift over time, your color rendition and vibrance may suffer and for this you should change the bulbs close to every year.

 

[dgasmd]

Jake:

I guess, the same question applies to it. First of, how did we come up with this one year rule? Second, what percentage change has happened by then that you can apply that across the board to all other bulbs? For example, a Ushio 10,000K bulb at 6 months of use has very very different percentage drop in everything from its original ones. A radium bulb at 6 months of use (same conditions and hours) would have a much different one. So, how do apply the same rule to all bulbs regardless of Kelvin or wattage?

 

[Mantis]

This thread is very timely. I was just considering the purchase of one of these meters as well.

Has anyone ever compared par values between a mogel 250 watt 10K XM to a double ended 250 watt 10K BLV? I'm sure the double ended par would be greater but I also believe the mogel would have a better light spread in a similar reflector. For example Reef Optix 3(double ended) and
Reef Optix 1(mogel)

 

[Shablin]

has anyone ever tried a 20k MH on one side of thier tank and a 10 K MH on the other with similar size frags of say acropora at similar distances under each bulb preferably close to the surface(assuming symmetrical water flow)? this would eliminate almost all water related variables and answer the bulb question some.

Id do it but I dont have a good quality camera yet. Could I get a government grant for this?

 

[dgasmd]

Shablin:

This has been done by several people. Actually, and for the life of me can't remember where I read it, someone took 2 20g tanks and placed a rack inside just the same in both. Also, the water flow inside was identical and both were fed from his main system, so water quality was the same. One had a 10K bulb and the other a 20K bulb of equal wattage, so the only variant was the bulb's output. There were some comparisons made between them in terms of color and growth rate. As expected, the 10K had better growth. Both colored up almost identical.

 

[Shablin]

Id be interested in reading about that if you can remember where you saw it.

Is reefing a common hobby for anesthesiologists? One got me (im an internist) into this hobby when I was a resident. He had two 400 gal homemade tanks in his basement with acrylic fronts and glass sides; pretty amazing!

 

[kevin gu3]

Don't you guys sleep?

 

[Aged Salt]

Kevin,:lol: & miss polyp-extension Bob

 

[AlgaeMan]

has anyone ever tried a 20k MH on one side of thier tank and a 10 K MH on the other with similar size frags of say acropora at similar distances under each bulb preferably close to the surface(assuming symmetrical water flow)? this would eliminate almost all water related variables and answer the bulb question some.

VA_Reefman used to have two 40g prop tanks. He had a 400w Radium and I believe the other was a 400w Iwasaki. If I remember correctly he said that the coral growth was the same in both tanks.

 

[JB NY]

Has anyone ever compared par values between a mogel 250 watt 10K XM to a double ended 250 watt 10K BLV? I'm sure the double ended par would be greater but I also believe the mogel would have a better light spread in a similar reflector. For example Reef Optix 3(double ended) and
Reef Optix 1(mogel)

SE lamps put out more PAR than the DE. The DE reflector is better though. So DE Lamp + reflector = More PAR than their SE counterparts.

 

[JB NY]

You know, I think I am going to bite the bullet and do this right. At least I will be able to tell what I am getting out of my bulbs, not to mention that it will give me the best indicator of when I need to change them. That brings up another question: what drop (percentage) in PAR is considered acceptable over time before you go and get a new bulb? That would really be what tells you when the bulb needs changing.

I would say around 20%, also there is a spectrum shift. Sanjay did some comparisons of lamps at different ages a while back.

One of the other nice things about having a PAR meter is you can see, apples to apples, how much light you are getting compared to others. Telling someone you have the acro up near the top of the tank is not a very good indication of how much light it is getting. Telling someone the coral gets 350 PAR is much better, as that value might be the tippy top of the tank for some and halfway down the tank for others. It would be great if many people had PAR meters as it would take so much of the guessing out of lighting our tanks.

 

[kevin gu3]

Someone (Steve Tyree?), suggested that you can get a year out of some bulb by having it on for 8 hours a day at the beginning of the year and extending that out to 12 hours towards the end.

Implies that increasing the hours can make up for loss of PAR. Also lower hours at start means it takes longer to lose the PAR in the first place.

 

[tsutaoka]

what about DE bulbs

what about DE bulbs

there's been a lot of discussions surrounding SE bulbs, but what does the group think about DE bulbs, what specific bulbs + reflector pendants.

thanks in advance

 

[pomme]

so would you guys say it would be better to have a 250w de 20k, and a 250w de 10k, over a 2x2 span.

or,
a 250w de 10k, a 150w de 14k, a 150w de 20k over the 2x2 span?