Greenhouse project

[surfy]

For slugs on the orchids the best way to get rid of them is manually picking them off.
If there are alot of them you may have to use some sort of slug bait to kill them.
Another idea is to use salt around the green house. Solor salt is cheap, just line the greenhouse with it. They could probably even put some epson salt around the base of the orchids.
I'm just throwing out ideas though.

Also look into Neem Oil for the orchids. It's not a pesticide but a natural oil from the Neem tree that most bugs don't like.

That is one nice greenhouse/prop house you have there

 

[dendronepthya]

Thanks for all the nice comments. I'm in the process of experimenting a bit with shade cloths to see which corals respond well and which ones do not. Most of my corals are looking overexposed, so I expect to see them look healthier in the next few weeks.

In the mean time, I wanted to share these two pictures with you. Here is an Acropora colony that wasn't doing so well in my tank at home. I moved it to the greenhouse on 8/17/2004. As you can see, it is very brown in color, and there is little to no polyp extension. The tips are very slightly purple, but nothing to write home about.

This picture was taken on 9/6/2004. The body has lightened considerably and the tips are clearly turning purple. The polyps have really come out in just a few weeks time. Note that this image looks a lot more yellow than the one before. It is due in large part to a 50% shade cloth covering the tank. I'm sure it would have looked much more impressive if the picture was taken in direct light.

 

[Jamesurq]

sweet! Do you have a par meter to figure out where you're at with each level of shade cloth?

 

[dendronepthya]

I've got all sorts of PAR meter readings!

This is a typical reading on a sunny afternoon (5pm-ish). A reading of "1114" is very bright.

This picture was taken on the same day under the 50% shade cloth. The "485" reading is about 50% of the "1114" reading, so the shade cloth manufacturers were pretty accurate.

This reading was taken on a different day when it was raining cats and dogs. Pretty dim reading of "45." What's interesting is, this is still enough light to sustain corals, you'll see in a second.

Just as a frame of reference, I decided one day to measure the light a few inches from my lights at home. Here is the reading under my 250W 10K. The reading is "654," but I usually get reading between "600" - "1000" depending on how close I really want to get to the bulb.

Here is a reading taken near my sump from a 55W PC bulb. A reading of "59" is not that far off from a dark and rainy day according to my light meter.

I found that the most interesting. Considering there are many reefs out there that use this type of lighting exclusively, I am confident that even in terribly dark situations, my greenhouse will have enough light to sustain corals.

 

[Jamesurq]

I was expecting a yes, or no....

Good answer!:lol:

That is facinating that a 55W pc would give off as much light as a cloudy day...

What might be fun, or at least interesting, would be to take periodic readings over the course of a year on an hourly basis (during daylight hours obviously) and seeing how much effective overall light your getting in comparison to say, a 250W MH run 8 hours straight.

Question is - how do you measure the sum? IE: does 2 hours of 500 PAR = 1 hour of 1000 PAR? probably not. Is there a point of diminishing returns? I think you'd be able to really get some amazing statistics for analysis with your setup there.

Fun stuff.

 

[dendronepthya]

It would be nice if the light meter I have could be automated so I could have it automatically log the readings every hour, but alas, I have to actually take the readings. Every time I go to the greenhouse, I keep a record of the light so when I have data from a full year, I can look back with clarity on the reality of my light situation and what I can expect for next year. It's not perfect data, but it's better than what most people have.

What I wonder is if corals respond more favorably to changing intensity over the course of the day compared to constant output from a bulb. A cloud blocking the sun can literally cut the intensity in the greenhouse by a factor of 10, so on a partly cloudy day, the corals will see a large variation in light intensity. It's not something I could find an answer to easily, but it makes one curious.

 

[willra]

I believe the first reading says "1174" -- even brighter!

Do you ever raise the shade cloths to a higher level so you can view the corals easier?

Looks great

Will

 

[Jamesurq]

In effect then, with the passing clouds, an hourly reading would be pretty worthless.

Is there a device that can "add up" the overall PAR on a constant basis?

I guess I'm not as well read as I would like to be on corals usage of light, as that point about changing intensity is way beyond me. Would be an interesting thing to figure out though - maybe we're doing it wrong with constant light?

I can see it now - random automated light movers mounted UNDER your halides with different shapes of varying shade cloths to emulate moving cloud cover...

Might look pretty neat too.

 

[NuclearReefs]

It would be nice if the light meter I have could be automated so I could have it automatically log the readings every hour

Isnt this the dream job some of these guys want to just be able to play in your green house Dendro? LOL.......

How much was that light meter you have? where did you get that one ?

Nathan

 

[kris_willard]

hitchin a ride! Awesome post.

 

[viveros1231]

wow!!! that is all i can say it is 4:20am and i am happy i couldnt sleep after reading this thread ..great thread awesome project love the pics. keep them coming...

 

[dendronepthya]

Is there a device that can "add up" the overall PAR on a constant basis?

Now that I think about it, I don't think adding up light reading would be a very useful measure. From what I remember about photosynthesis, a threshold intensity must be reached to trigger a photosynthetic response. Until that activation point is reached, no reaction occurs. Let's say that the reaction starts at an intensity of "50." If you were to provide 8 hours of light that was only "40," the organism would basically derive no energy from photosynthesis. If you provided "500" for an hour, I think all you would get is one hour worth of light, not ten hours worth of light. I think this is how it works, but I can't remember for sure. It's been a while since I was a biologist.

How much was that light meter you have? where did you get that one ?

I purchased mine from the manufacturer, Apogee Instruments (http://www.apogee-inst.com/bqm_spec.htm) I have their Quantum meter with remote sensor and calibration switch. If you notice on my unit, there is a separate setting for both natural light and artificial light. The nice thing about this unit is the detector is submersible. The reading at the bottom of your tank is probably one tenth the intensity on the surface.

 

[wonrib00]

So, since you have taken the reading when it was raining cats and dogs and it was equivenant to a 55w PC, the question still remains: Are you going to add supplimnetal lighting for the cloudy days? You also have to keep in mind that the intensity of summer sun is going to be much higher than that of winter sun. You may look into different grades of shade cloth. Use one that allows more light in when the sun is farther away from earth.

 

[Jamesurq]

how about you wire that PAR meter up to a switch that will activate a garage door opener that will either cover or uncover the tank with your shade cloth depending on a set PAR range?

NOW WE"RE TALKIN!

 

[dendronepthya]

Are you going to add supplimnetal lighting for the cloudy days?

If I had to guess right now, I'd probably say no. Regular cloudy days don't bother me much. I can get a reading of "200" - "400" depending on the time of day. The rainy day reading I showed earlier was literally the lowest outlier in my records. Even if there was a week-long rain storm, I am confident that the corals will survive.

You also have to keep in mind that the intensity of summer sun is going to be much higher than that of winter sun. You may look into different grades of shade cloth. Use one that allows more light in when the sun is farther away from earth.

Yes. That is true. I am curious as to what kind of readings I will see during the winter. My plan from the start was to have shade cloths in the summer, and simply remove them in the winter to allow maximum exposure.

As far as adding more shade goes, it's actually very simple. I can simply add another layer on top of the existing one.

Do you ever raise the shade cloths to a higher level so you can view the corals easier?

I have the cloths higher than the picture I posted earlier, there is enough room for me to comfortably reach into the middle of the tank. I set it to the height that is the best combination of coverage and ease of maintenance.

how about you wire that PAR meter up to a switch that will activate a garage door opener that will either cover or uncover the tank with your shade cloth depending on a set PAR range?

That will have to wait until greenhouse v2.0

 

[fairweather]

I have thought about a small house but normal sunlight seemed to grow algea very quickly on a test tank, what can be done to prevent this? I tried to read the whole thread but its very long which this was probably answered already if so just say its in the thread. thanks Than

 

[maxxII]

normal sunlight seemed to grow algea very quickly on a test tank, what can be done to prevent this?

Algae grows where there is what it needs to survive....
light and nutrients. Obviously you cant go w/o the light, just make sure your water is as free of nutrients like phosphate and nitrate as possible. This should help keep algae as minimal as possible.
Look into RO/DI units for your water source.
Nick

 

[Treeman]

I have a 200 sq. ft GH now and never had a problem with algae. Like maxxII said it is a matter of nutrients.

I just about have my next GH up and running and I put in a concrete sump to help cool it.

Matt

 

[Lostmind]

On the thought of starting photosynthesis in the corals - How about a 1000w MH fixture on a light mover running across all the prop tanks in the mornings to give the corals a kickstart?

Just a thought. I am really interested in light movers lately

 

[Lostmind]

stupid double post