View Full Version : GH Film
11/09/2005, 05:28 AM
I have a GH that was totaled by hurricane Wilma. I am rebuilding the GH and I am trying to find a new or different plastic covering. Here is a link:
I was using the K50, But I was unsure if the K50 IR/AC or the KoolLite380 would be better.
The KoolLite blocks all UV below 380 nm. But would it cause less flourescing or in some other way cause a problem for the corals long term survival / adaptibility?
11/09/2005, 11:09 AM
In general... you want a covering that has minimal alteration of the physical properties of light. Namely: over 90% light transmission and over 90% UV transmission
I would not take the KL380 for free ;) The UV blocking is just horrifying for many of the corals you are likely to want to keep/grow.
Frankly... the other glazings admitting only 77% when new and getting worse over time is also quite concerning to me.
but only you can tell what is best for you by measuring (light meters) the sun under which your greenhouse sits.
Hence the common advice as per above to admit max light in and shade over individual tanks/pools/species as needed.
Terribly sorry to hear about the storm damage too my friend. Just dreadful :(
11/09/2005, 12:27 PM
Thanks for the info. I thought the same thing about limiting UV light. The reason I was considering it was because it would lower the temp in the GH by about 10 degrees. The GH gets to be about 100 plus degrees during the summer even with the sides open.
I had 40% shade cloth before and I still got very good growth. But thought it was to much shade.
Thanks about the GH. It was a real bummer when I got here during the end of the storm. But I already knew it was down just by the amount of damage and wind at my house. I am rolling with the punches here. I ordered a new GH today that should withstand up to 140 mph. If it gets that high I am heading to the hills with my tail between my legs :D
11/09/2005, 12:36 PM
I understand/know from many years of working in GHs how unbelievably hot it gets! I had days in February with a foot of snow on the ground outside but temps still over 100 inside for the sunny day and lack of (winter) shadecloth. Indeed... summers are brutal. Yet I never had tank temps go over 84F
Water temps should not be an issue mate... with shade cloth, recirc fans, exhaust fans... geo if needed and/or dessicants on drip trays in front of your shutters... they are all easy/cheap fixes to insure cool enough water temps.
Indeed... the same is NOT true about the ease/cost of producing more light (daylight and UV) for lack of a proper GH covering.
You are on the right track, bro... trust your instincts here. You want max light (total and UV) as per above. Filter down as needed.
11/09/2005, 12:57 PM
Originally posted by Anthony Calfo
Indeed... summers are brutal. Yet I never had tank temps go over 84F
I wish that was the case here. I get so much heat from the sun down here that I fight it constantly. Some days 90 degrees and 70% + humidity...evap coolers don't do anything on those days. With 2 layers of plastic and 40% shade cloth and evaporative cooling on the tanks and!...During the heat of August I had to put a 50% cloth over individual tanks also.
11/09/2005, 01:30 PM
Actually.. we have the same bad weather up here in the NE US, bro... humidity in our region is brutal... suffocating indeed and well over 70%. 90F days that last for weeks/months each summer.
Your situation is not unique. And the evap cooling is/can be boosted by the use of dessicants on drip trays (I recall it was pioneered by FL state universities in fact!). Usually just cheap-o ($4 per ton) Calcium Chloride poured in trays to rip off moisture so that drier air can reduce heat when drawn over your aquariums by the exhaust fan on the end wall. This is for humid climates, mate. You can find the supplies/info in GH supply catalogues (especially the SE USA companies)
03/21/2006, 11:02 AM
Not sure if this will get a response or not, or even if this is the best place for this, but it seems relevant so I thought I would try.
I too am working on a project of this sort, and am looking for all of the information I can muster, so please take this as a research discussion. If its alright I would like to run some ideas I have by both of you to see if what I am finding is "real world" correct.
Is there a film that you recommend?
You don't recommend the KL380 because of the lack of UV transmission. Is this because it does not live up to its billing or do you think it is necessary to get light below 380? From what I understand about this film it will allow 92% of the light above 380 to enter, and block ~78% of the light below 375. Based on those numbers it would seem to be ideal for what "most" corals need. I agree there are some that need other lengths but anything below 350 I always thought was detrimental.
I will get to more depth in a min, but I do agree that the violet (380 - 430) end of the spectrum is absolutely vital to coloration, and that some UV (~355 - 385) is needed to both sustain the symbionts needs and to create fluorescent pigments.
My questions come from pretty intense research on studies of light and its affects on both corals and their symbionts. While I have relied on what I have found from these studies I am absolutely open to your respected opinions. What I have found suggests that light in anything more than small to reasonable amounts below 360 will cause the same net effect as a sunburn to the corals. This causes them to produce a mucus to block the light much as we would create melanin to block the light from our skin. My understanding is that this is growth limiting as well as deleterious to both the coral tissue and the amount of zooxanthellae that the tissue can maintain, because the mucus smothers the zoox from both light and nutrients.
If this is an interesting discussion I would love to run some more by you as well. I have been working on a business plan for this for about a year and have had some great responses by both marine bio types (professors mostly) and business types (SCORE, SBA, and some fuding types). I have not had much interaction with RC community types as I must admit the wealth of knowledge here is somewhat intimidating and I have spent so much time absorbing I am just now feeling as if I can make reasonable contributions.
I have just gotten the funding I need to get setup and am in the process of prepping the site and ordering supplies, so any help you can provide would be greatly appreciated.
03/21/2006, 11:24 AM
Another thought to add. I had investigated and discussed the idea of using desiccants, (road salt) to dry the incoming air, with some engineers at our local university (of Illinois). They tell me that the desiccants won't add much (if any) net cooling because as we remove moisture from the air, it heats up. Conversely, when we add moisture to the air, it cools down. So their hypothesis (theory?) is that the air comes into the desiccants hot and humid, the desiccants pull moisture out, thereby warming the air even more. The warmer (but drier) air passes over the evap pads which add moisture but cools the air and we are basically back where we started.
So, point blank,
Anthony, did you use desiccants on your gh? Know anybody who does/did?
Is the reason desiccants might work (despite the warmer air temp) is the simple fact that the air is drier? So basically, I would have been discussing a different principle with the engineers, ambient air temperature. Whereas the issue we didn't really discuss was the amount of humidity in the air and it's potential to hold evaporative water from our culture vessels, thereby adding a net cooling ability of that water.
03/21/2006, 07:25 PM
I don't think Anthony is around here much anymore. But we can wait and see.
I have Klerks K-50 on the top, two layers. On the end I put one layer of Koollite-380 and one layer of K-50. I was hoping it would cool the GH some late in the day and also block some of the heat later in the day.
03/21/2006, 08:29 PM
Hi all and thanks for the thread !
I have actually been very seriously (some might even say obsessively ;) ) thinking about starting a greenhouse project like that in China where I live and I'm obviously very interested in the wavelength/coral coloring issue.
Raaden, thanks for sharing the results of your research. Doesn't matter wether you are right or wrong it is just great to be able to discuss it... Actually what would be even better would be to be to get the very informed opinion of a respected professional such as Anthony (hint, hint );) By the way Anthony, any info on when The book of Coral propagation V2 is scheduled for release ?
Rick, I just went through all 22 pages of your setting up a few days ago with great pleasure....I could just picture myself taking the pics :D Concerning the evaporative cooling, i"m no expert but from what I understand what lowers the temp is the moisture being evaporated from the air itself, the droplets of water needing a lot of energy to go from aqueous phase to gaseous phase (like it takes much more energy to melt up ice to water even with only 1C difference, than it takes to heat up water to water just the same 1C). Assuming this is right, i would disagree with the removing moisture=heating up air since in my mind it is the exact same process which lowers its temp while at the same time increasing its potential to evaporate more humid air...I am no engineer though so I do not feel very comfortable disagreeing with one since I might very well be totally, absolutely, dead WRONG :rolleye1: ....Would love to get more info on that though since the summer temps here can go over 42C (that would be close to 105-110 F I guess) with 80-90% humidity...
Finally Treeman, I went through your setting up with great pleasure too...until the hurricane pics which made me feel a big hollow in my chest :( ...Like for Rick I could just imagine myself taking these pics after a Typhoon hit my not yet existing GH...Congratulation on not abandonning though and hope it won't ever happen again to you !
03/22/2006, 01:02 AM
snadaud- According to the engineers I talked with (like you, I am no expert), it is evaporating water which lowers the temperature of that WATER. Whether that water is in an aquarium, a reservoir for an evap pad, a lake, wherever. In our tanks, we use evaporation to cool the tank water (water turns from liquid to gas, taking heat out of the water). In an evap cooling system, the water is pumped across the pads and gets evaporated which cools the water in the reservoir which in turn gets pumped across the pads (water turns from liquid to gas taking heat out of the water). As the incoming air flows across the now cooler pads, the air gets cooled (plus picks up moisture as the water evaporates from the pads into the air). The water in my reservoirs for the evap pads is very cool to the touch when the shutters are open and the pads are receiving water, usually in the 60's F or 70's F when it is over 90 F outside temp. The only drawbacks with this system is that when the ambient humidity gets too high, the pads become less effective because the incoming air can't absorb much more moisture and they don't cool the incoming air as well. As the air passes the pads, it also picks up moisture, which lowers the ability to pick up evap cooling from the tanks themselves (the air coming into the greenhouse is now more humid). If the pads are working efficiently, the air temp inside the greenhouse will be kept low enough that it won't matter if we can evaporate water from the tanks or not.
The opposite function is also true (according to the engineers), that if we remove water from the air, the air heats up. What you are saying is true, it takes energy (heat) for water to change states, from solid to liquid to gas to liquid to solid . The difference is in which way the energy (heat) flows, either from the air into the water, or from the water into the air.
There is much more discussion about the cooling aspects here, about 35 pages
be sure to check out the psychometric chart, print a copy for yourself, it will come in handy.
glad to see your rebuilding is coming along.
Just to add, I am using the Klerk's K-50 clear (all the way around) as well. I find that I have to shade everything with the exception of Sarcophyton elegans, but those corals can grow in ankle deep water in the tropics. I don't have any stonies stocked in any tanks yet either. Even in winter, I had some Actinodiscus mushrooms trying to bleach. Very strange though, there would be some trays with one or two mushrooms trying to bleach, and the rest of the tray would be fine. Other trays, the entire population would try to bleach. Other trays, the entire population would be fine. All trays in the same tank. I haven't lost anything (YET), so I am grateful for that.
P.S. You going to IMAC this year?
03/22/2006, 10:04 AM
Welcome aboard! I won't even discuss the evaporating coolers. All I know is that it will cool the GH if the air temp and humidty are not to high :)
I don't think I will make IMAC. I have already commited to a ski trip to Winter Park in April. If I get back and have enough money in the aquaculture account I will go. I lost and spent a lot of money because of the storm so that will dictate what I can do :(
03/28/2006, 07:08 AM
Thnaks for the info everyone, helps a lot!
04/01/2006, 10:20 PM
Took me a while to go through the thread but it was definitely worth it even though I have to say that I'm even more confused than i was concering the evaporative cooling...
Guess I will take treeman advice and just stick to the fact that it cools the air if it's not too humid ;)
01/19/2007, 08:47 AM
WOW - Same here head spinng around.
After all the reading I am should I do it - na Yes I should. hey invested all the money in equipment (not all the right stuff) and now thinking of not bothering. Well my initial ideas keep changing and the GH for a site was only an option as the shed i was to use fell through.
Just mind boggling.
You guy are at the forefront of preservation. Love to be a member joining in Europe.
Will see what happens.
Treeman - you are an inspration as someone who can fight back at what nature deals.
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