Jump to content

Lightburn


ghostface

Recommended Posts

Has anyone ever had their MH lights burn corals? i seem to have a few acros and montis losing colour and having tissue loss where one particular light shines on them. it only happens where the light hits them, not on the undersides. not all corals under the lights seem to get "burned" though... my water water params are all good. almost no phos, no nitrate, ca 450 kh 8 etc. only thing wrong in the last little while was my temperature being around 20-21, as my digi thermometer was reading about 3 degrees too warm.

its not a new bulb, its a 150w de Arcadia 10k. it is in the same fitting with the same UV glass as my other two which don't seem to do the same thing.

any ideas?

scuse the bad pic, but you can see that the coral on the left is brown on one side, blue around the middle and dead on the side that the light was shining on

fade.jpg

Link to comment
Share on other sites

Burning corals is quite common. even a 150w halide will burn coral if they are not used to the light. done this plenty of times myself.

temp seems way to low.

It also could be the lack of light as corals tend to go lighter and the then die.

Try moving them up higher.

Link to comment
Share on other sites

I dont think it will be light. Probably something to do with the frag itself or the way it is in the sand.

As long as the UV protection is there it sould be sweet. How many watts?

150w 10k.

there are half a dozen corals doing the same thing. i've just moved those frags to there, under a different light. the ones that are doing it were all in plenty of light. it seems strange that it is only happening to some acros and not others, and it doesnt seem to matter if they are 1 inch long frags or fist sized pieces. it is happening to new additions and bits that have been in the tank for months.

gonna try a diff bulb in that fitting soon :-?

Link to comment
Share on other sites

is that staghorn really that blue on one side and brown on the other? or is it just the picture?

if that is the real colour then i would say something wrong with the light. turn it off and see if the corals ger better.

Try moving them up higher

if it is the light then that will kill them for sure!

Looks like UV burn

that what i would say too

temp seems way to low.

only a non diver would say that :D

Link to comment
Share on other sites

Quote:

temp seems way to low.

only a non diver would say that

i actually do dive, in my tank. :D

Based on the my reseach for MAF/Erma.

The lower temp limit fo the most cold-tolerant reef corals appears to be about 20c. This is about temp of midway atoll which has the northern coral reef. although a few reef animals can live in colder water , most cannot. The average annual temp of most coral reefs is around 27-28 c which seems to be the optimum for coral growth(barnes et.al 1995, clausen 1975. weber white 1976) the commonly advised mini-reef temps of 22-25 c are stressing most animals unnecessarily and in some cases severely.

Mostly all the corals we get come from indo pacific which has temp over 25c. so anything below is not advisable.

could explain some of your problems with the acros.

Problem could have happen when the temp dropped. how long was it at 21c? The low temp might have stressed the corals and taken away the uv protection.

Link to comment
Share on other sites

:roll:

be nice to each other :D

Mostly all the corals we get come from indo pacific which has temp over 25c.

whats the water winter temp. in the northern island groups of tonga?

the red sea is another very good example of cold water during winters (brrrrr)

actually do dive, in my tank.

found any ship wrecks lately :D

cold water holds more oxygen, calcification takes place until you reach around 17 degree. winters do exist even in the tropics with water temp dropping quite a bit. its never 26.4 degree all year around (except a few places but there the temp seem more like 29 at all times which doesn't seem to great either)

what do you add to the tank

good question but did you look at his posted picture? the colour is in credible ranging from brown to pastel light blue depending on the light source. most be some additives that are able to do that. :wink:

Link to comment
Share on other sites

whats the water winter temp. in the northern island groups of tonga?

i quess it is low at times.

we dont get many corals from the northern island groups of tonga if any.

Further reading from a book i have.

There is the very real problem of the mixed fauna and flora in many of our systems. aquarists tend to mix animals from different geographical areas with joyous abandon. this results in a tank full of animals with a variety of range of tolerance temperaturs found in these localities.

The organisms from these areas have generally do not have such wide temperature tolerances and may survive in these lower temps.

relative to the conditions found at the centres of their distributions, however they do not thrive under these temperatures. furthermore , animals from the diverse centers of distribution generally do not have such wide ranges of tolerance and cannot tolerate significant reductions of thir metabolic rates. as a result, they have a reduced tolerance for thermal variations.

The Great Temperature Debate

http://www.reefs.org/library/article/reef_temperature.html

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...