Sunlight UV radiation & SPS

Ok a quick question I am in the process of setting up an outside tank.

The roof of the shed and one wall where it is housed will be covered in clear polycarbonate sheeting but all the sheeting here has a UV coating that knocks out 99% of harmful UV radiation but lets through 99% of the light.

I was wondering what everyone's thoughts are in regards to eliminating 99% of the UV radiation.

Cheers

Well don't MH lights come with a glass shield that is there to block out UV radiation?

I don't think it's a problem. But I am purely speculating as well. Will be following for the answer from one of our experts.

I think you are probably on the mark I believe that most DE MH bulbs run a glass shield and most SE glass bulbs run a coating.

It will be interesting to see what the general consensus among everyone is.

Cheers

HQI bulbs require a glass shield, however there is a seller on ebay that has HQI bulbs that do not require a glass shield at least thats what he states. Mogule bulbs (single ends) do not require any shield the shield is built into the lamp.

Rhys123 FIRST OF ALL WELCOME polycarbonate sheeting now has 99% of UV protection but as time go by the tolerance go down i live in a country that sun have down grade uv protection glass and not polycarbonate i thing to be save you should use a uv light with the tank

I think it would be a good thing to eliminate the UV. But I agree with Marvik, the sheeting will deteriorate over time and let more through. Could you do a glass skylight above it?

Cheers guys

Skinz

The area that has to be covered is to great for glass the roofing section just by itself is 3meters by 2 meters the wall section is 2 meters by 3meters.

I think it won't matter much and could actually be beneficial if the UV radiation is eliminated I believe that 1 meter of water more or less accomplishes the same.

Cheers

I dint think having the UV shield will hurt anything.

Its pretty interesting that we worry about filtering out UV in our tanks but in the wild there is no UV filter. UV light does penetrate water but not very far.

There is speculation that corals develop various pigments to protect against ultraviolet light which would make sense because UV does exist in the wild. In our tanks however, light bulbs produce much more ultraviolet light than is found in nature, and the UV they produce is in the more dangerous spectrums. Hence the need to have ultraviolet light filters, because UV is harmful to corals just like it is to every other animal. So in short, corals do not need ultraviolet light, and filtering it out is beneficial.

I'm not sure if they need small amounts of UV for some metabolic process, but it appears that they grow perfectly fine when UV filters are used.

I've read that some MH can produce more than 60% compared to sunlight. I don't see the harm in blocking out some of the UV's though, especially if you have species from deeper waters than what your tank will be.

i agree, i have heard elseware that the uv actually does more harm than good. yet still some people put uv leds on tanks... there has got to be some reason for that. i wonder if they are getting any benefit from it?

Kdino

Originally Posted by Kdino

i agree, i have heard elseware that the uv actually does more harm than good. yet still some people put uv leds on tanks... there has got to be some reason for that. i wonder if they are getting any benefit from it?

good question! anyone know why????

btw Kdino, glad to have 'ya on board!

I dont.

What uv leds are people putting on there tanks? i dont think ive ever seen that

They're probably using longwave UV LEDS (aka blacklight) which is relatively harmless. longwave UV will make many coral pigments fluoresce so they make the corals prettier. However, the shortwave UV (UVB and UVC) is nasty and causes DNA damage, so never put this type of bulb over your tank!!

that makes sense spiny. alot of the actinic bulbs we use are very close to UV and some do dip into UV but its UV-A as your talking about

see this video and watch the corals sun bating and the ozone layer ? plus the uv and we all don't put the sps lps and other out from the tank?

What he doesn't tell you though is that extreme low tides aren't a frequent occurrence and ELTs at mid-day are even more rare. On most reefs you get 1-2 ELTs a year (which occur daily for 5-6 days), but may only get one event that happens at midday every few years. The kicker though is that when it happens it's not uncommon to have significant coral mortality. In one particularly nasty case a few years ago 50-75% of the corals on one reef in OZ were damaged. You can't even begin to assess that though until about 4-5 days later, so pictures from the peak low tide don't tell you much about how the corals fared.

It's pretty easy to spot the reefs where these events occur because the reef flat will be very flat with lots of open, uncolonized space and will be dominated by small examples of weedy species. Any large LPS type corals will have flat tops with dead centers. The coral he stops and examines saying it's a good size looks to be only about a year-old colony, so this could very well be its first ELT.

As for actual UV, there's no question that shortwave UV is harmful to corals. They do produce mycosporine-like amino acids to protect themselves from UV, but these are not colored pigments. There is no evidence so far that the production of actual colored pigments is the result of UV exposure. There's no reason to believe that corals need UV for any particular reason and they grow just fine and color up just fine under low-UV light sources. There's no need to be concerned about using a UV blocking panel.

"hello little gorilla crab, nice to meet you." douche.

I saw a tank a while back that had a reef crest area that was partially exposed to air every once in a while. It may have been Borneman, I don't remember, but whomever it was claimed it aided in some way.
bill

Originally Posted by greenbean36191

What he doesn't tell you though is that extreme low tides aren't a frequent occurrence and ELTs at mid-day are even more rare. On most reefs you get 1-2 ELTs a year (which occur daily for 5-6 days), but may only get one event that happens at midday every few years. The kicker though is that when it happens it's not uncommon to have significant coral mortality. In one particularly nasty case a few years ago 50-75% of the corals on one reef in OZ were damaged. You can't even begin to assess that though until about 4-5 days later, so pictures from the peak low tide don't tell you much about how the corals fared.

It's pretty easy to spot the reefs where these events occur because the reef flat will be very flat with lots of open, uncolonized space and will be dominated by small examples of weedy species. Any large LPS type corals will have flat tops with dead centers. The coral he stops and examines saying it's a good size looks to be only about a year-old colony, so this could very well be its first ELT.

As for actual UV, there's no question that shortwave UV is harmful to corals. They do produce mycosporine-like amino acids to protect themselves from UV, but these are not colored pigments. There is no evidence so far that the production of actual colored pigments is the result of UV exposure. There's no reason to believe that corals need UV for any particular reason and they grow just fine and color up just fine under low-UV light sources. There's no need to be concerned about using a UV blocking panel.

excellent points you brought up greenbean ... I'm in agreement with you.

Originally Posted by funkpolice

"hello little gorilla crab, nice to meet you." douche.


bill

yeah...he lost my respect at that moment...