Too much light?

[TAXMAN]

Ok. This may sound weird. Can you have too much light on a tank? I am having a problem with my Mushrooms, Zoanthids and Finger leather. Even with the shrooms in the shade they will not come out. They stay drawn back. The Zoanthids have lost a lot of color and only come out about half way or less, but are still reproducing. Other corals like Montipora caps and Digi's seem to grow ok but should be faster IMO, but also have lost a little color. The Hard corals like Acro frags seem to all but brown out. I have now lost 2 birdsnest frags due to bleaching and loss of tissue. Even on the sand bed. I have placed them at all depth's..
My candy cane has gone from 3 heads to about 25 heads in about 4 months. So it likes the light I guess. Coraline will barely grow at top rocks. Very light pink but does well in the shade and under rocks. Lots of dark colors and types in the shade. Walls are crusted over but very lightly and very light pink. Near white.

On my 180 I have 3 400W MH with 6500 bulbs and a 660VHO with 3 60" bulbs. 1 is an Actinic and the other 2 are 50/50 bulbs.
The run times are here.
7am VHO on, off at 10pm
8am Center 400w on, off at 7pm
9am outer 400's on, off at 5pm

I am already considering removing the VHO and putting 20k bulbs on the 2 outside 400W MH's and leaving the center a 6.5k .. Or would placing all Actinics in the VHO help matters? I am kinda lost here.

All water parameters are ok.
Temp 80-82
Ca 420
Alk 9-10 dkh
Mg 1500+
PH 8.4
Ammonia 0
Nitrate 0
Nitrate 0
No test kit for Phosphate. I run carbon 24/7 since I had a coral problem a while back.

I hope that someone has some idea for me.

Johnny

[adamRS80]

I've had a similar problem in my tank, and it did seem to help by raising the lights a little bit. I'm not sure if that's an option for you though if they're in a hood. It does seem like you have a large amount of light but isn't the amount of light we produce with Metal Halides, or any other means much less in intensity than the sun? Although I can't offer as much help as some of the experts, I wouldn't think that you have too much light...maybe it's all too close to the tank. I've wondered about the same thing myself...my tank is much smaller but I have 1 250w 20k about 5 inches from the water surface, and I've had the same lack of coralline on my rocks. I've had a few Acros. that were doing great just whither away. Most everything else is doing well though. If you're replacing your bulbs anytime soon you might try using two 20k and one 10k, then leave the VHOs off for a week or two and see if you notice a change. Using any actinic with the 20k in my tank makes it way too blue looking. If nothing else you should notice a change in color using the 20k blubs. I wish I could offer you more advice. From my limited experience your water parameters look right on. Do you do regular water changes? Maybe your tank is lacking somethign that could be supplied by a water change every month. I'm sure you do water changes but I know some people choose not too and still do good. Hopefully somebody else can give a little more info. Good luck.

[Ram_Puppy]

from what I have read on here and live aquaria, the higher the k the better the color, the lower the k, the better the growth... I am not sure how 'true' that axiom holds up across the spectrum of coral species. I know that some of my friends grow carnivorous plants, and run fresh water planted tanks under 6500K lamps, it was my impression that in the aquarium community, they were mostly for fresh water applications. But if there is one thing this hobby has taught me, there are no certain rules, what holds true for one may not for another.

If you are woried about the quantity of light your pumping into the tank, why not un-plug one of the halides for a couple of weeks to see what happens? with 180 gallons and 3 400 watters, you come out to about 6.6 watts per gallon before you add the VHO's, T5's and so on... which is right in the 'zone' for what is arguably a very 'loose' form of determining the amount of light you have on your system.

I know I have about 9.8 watts (a good percentage of it is actinic) per gallon over my little 30 hex, and so far I am only running 4 hours a day on it, but the softies have showed no negative signs... I know that doesn't say much considering the short period of time it has been running (less than a week.) but I hope it helps.

[TAXMAN]

I do water changes every week. about 18gal. I have made the last two water change cycles at 2 wek intervals to see if it might help. I can raise the MH's about 3 more inches. They are in a hood. I'll try that and see what happens. But I know I need more Blue light to maybe bring the colors out in the hard corals.

[StephenA]

How far are your lights from the water?

[GaryP]

Taxman,

By my calculations you have about 10 watts/gal. That seems a bit on the high side. I have always tried to stay in the 6-8 watt/gal. range. My SPS tank is at about 6.5 watts/gal. That's a little on the low side in my opinion. I'd like to upgrade my 250 watt MH to 400 but I would have to do something about cooling before I go there.

That brings up another question. What is your temp.? Another thing I noticed was that you are running carbon 24/7. From what I have read that is generally not a good idea as it strips a lot of nutrients from the water. Carbon should usually be run for short periods of time. The only time it should be run 24/7 is when your tank is going through some sort of an upset as you had mentioned. If the upset is resolved, I would recommend cutting back on your carbon use.

Gary

[lax]

i dont think that you have to much light, i think that your mh lights are to close to the water.

i have a nano cube with 15 watt/gal of hqi mh, which is more intense than single ended, equating more like 20-25 watt/gal in ONLY 10 GALLONS. i only have 9.5 in of water depth, b/t surface and sand bed. i run my 13kk light 15in. above surface, no hood. i have great coraline algae, acro, zoos, shrooms, toadstool, monti coloring and growth. in fact everything is growing so fast i'm gonna have to start fraggin like a mad man in a week or two.

my water parameters are almost exactly the same as yours except my temp is constant 78. also like gary said, you only need to run carbon during 'upset' periods. if you change your 6500k lights to 20kk, all you'll really be doing is creating a fake coral color being more blue and lessening yout total light spectrum from more of all colors to just a blue spectrum almost nullifying all of the other spectrums. imo just raise your lights up and be patient.

[Brett Wilson]

I agree with the bulb distance to water surface maybe causing issues... but I don't see where you state what that distance is.

I do not think watts-per-gallon is a good measurement for light though.
If you think about it what really matters is bulb wattage, ballast used (some overdrive bulbs), reflector type, distance from bulb to water surface, distance from water surface to corals, clarity of the water, and what type/brand/color-temperature of the bulb(s) you are using.

I had a 45 gallon breeder with two 400W halides (5" above water surface) and had most of the different types of corals with great success.
That would be 20 watts per gallon if you calculate that and the tank was only 18" deep. But those were 20,000K radium’s, they don't produce as much par as your lights.

Think about this scenario:
Using the exact same bulb configuration: At 8" depth in a 20 gallon tank you will have the same brightness as you would at 8" depth in a 450 gallon tank. Of course in that 450 gallon tank you would want more than one light to get an even spread and that will give you multiple lights shining on some of the same corals.
For reference I think Jim Norris had more than 10 watts per gallon.

The Iwasaki 6500K halides are some of the brightest and most yellow bulbs used in the reef hobby and people commonly complain about having brown corals. You might try some 10000k's if you are unhappy with the colors. The Iwasakis are known to produce the most growth though....

The carbon might be a problem but I run it 24/7 as well sometimes. How often do you change it out?
You might consider double checking your temperature probe as well.

Here is a chart of different bulb outputs on different ballasts... (250 watt bulbs)
http://www.reefcentral.com/forums/showthread.php?s=&threadid=254667
Notice how much PAR the Iwasaki's have compared to the rest.

I like to see how other people do it with big tanks; check out reef keeping’s tank of the month. You can also look at back issues.
http://www.reefkeeping.com/issues/2004-05/totm/index.htm

There is also a book out that is nothing but tanks, their equipment, and all kinds of info about each of them. I can't remember the name though...

Last but not least, there is a wealth of knowledge in the lighting forum on reefcentral..
http://www.reefcentral.com/forums/forumdisplay.php?s=&forumid=212

I hope at least some of that helps...
-Brett

[TAXMAN]

My lights are roughly 10" above the water. I can go up maybe 1" due to the way they are hung in the hood. I have seen a lot of peoples lighting and they are usually the same or lower than mine.

As for the Carbon, I did have a few weeks with a coral problem. I beleive it is ok now. But when I have asked aout the carbon running, most people run it 24/7 and just keep it clean and change it out about every 4-6 weeks.

So basically I feel that I may have to get rid of the VHO setup. That would be a 420W drop in lighting. Then place the 20k bulbs on the outside MH and leace the center with a 6.5k .. This will give me better corraline growth due to the spectrum and should help the corals some.

[Brett Wilson]

I wouldn't sweat the 10" at all. That is far enough I think.



As for the Carbon, I did have a few weeks with a coral problem. I beleive it is ok now.

Elaborate more on that coral problem please...

[TAXMAN]

Thanks Brett.

The coral problem was most of my softies shriveled up and lost color and the SPS would bleach and start to loose tissue. I tought it was the chemical battle of the different types of corals, but I found my temp probe to be bad and the tank was running from 84-89 for about 3 weeks. Thats when I put the carbon in and then found the temp problem a few days later. I only left the carbon in due to most of the people that replied here and on RC run it all the time. Just to keep the water clean and not take chances I guess.

[Brett Wilson]

yeah, I prefer clean water myself, just like where the corals live in nature - nutrient depleted water.

[SueT]

Taxman, I ran 400w 65k iwasaki's over a year, several years back. Basically the only reason I got rid of them was the heat they put off and my chiller couldn't keep up. During that time I had some of the best growth and coloration I've ever had in my acropora collection. I opted to go back to the 250w iwasaki's. I was able to raise my canopy and lower it to acclimate my corals. This was on a 120g with 2 lights. I know that several of my sps friends have had 400w iwasaki's but most have also switched to some sort of 10k now. Myself included.{Thanks to Jim Norris}. I also run carbon 24/7 and just started using ROWAphos too.

I don't think your temp is bad but I wouldn't let it get any higher. I keep mine at 77-78. I think I have to agree with the ideas your lights may be too low. I literally burned my arm working in that tank when I had the 400w iwasaki's on it. If it could burn my arm I'd hate to think what they can do to corals.

[Tim Marvin]

I run my halides 5 inches from the water. The lower the better in my opinion. One thing that everyone is overlooking here is water changes. Your doing 18 gallons per week? That is 10% if you had nothing else in the tank. If your tank is loaded with rock then you are doing more like a 20% or more since the rock is displacing a lot of water. If it is 180 gallon tank full of rock you probably only have 80-90 gallons of water. Times that by 4 weeks and your doing 80% per month! I used to beleive it was helping my tank by having such perfectly clean water, but I couldn't have been more wrong. I lost a lot of the mushrooms I had, most corals shiveled up to near nothing and sps turned brown. Even the anemones didn't like it. At the same time I had a tank, that I neglected, (IMO), and after scaping the green off the glass I realized it was exploding in life and growth! I learned that too much water changing can also be a very bad thing. I quit changing so much water and everything came back. I don't even do water changes on the prop tank any more other than making up water as I sell frags so it realistically gets about a 20% change just from selling frags. I did up grade the tank system recently to the Norris prop tank so it got a small water change. What I am trying to state here is: too much water changing can also kill your livestock. Stick to about 3-5 gallons per week and see if that helps. Maybe not even do a water change for several weeks before you start the new schedule.

[Brett Wilson]

Good points Tim; I totally ignored that fact.

[prof]

How is your water flow? Too much or too little can cause what you are describing.

[Tim Marvin]

Birdsnest need intense light and high flow. They would die on the sandbed anyway.