let the insanity begin

[rick rottet]

Hello Anthony, long time no talk to.
I want to thank you for all the time you have spent answering my "pesky" questions. Though we have never met, you have done more to help me with the construction of this facility than anyone else. I ended up deciding to run the original thread in my local club's forum but here is the link.
Thanks again, my friend.
http://archive.reefcentral.com/forums/showthread.php?s=&threadid=465933

[Anthony Calfo]

outstanding, my friend. 'Tis very good to see and read!

A very special thanks to you too for being willing to give as you have taken/learned by posting your efforts/progress for others to read and learn from.

I look forward to meeting you in person.

Anthony

[rick rottet]

Thanks for the encouragement Anthony. The day we meet will be a "red letter" on my calander.
P.S. Dont worry, I still have more questions pending- heehee.

[hcs3]

anthony visiting central illinois would be a grand day indeed!

anthony, drop me a message if you are ever out this direction (shicago, indy, st louis). perhaps we can get the local club involved and cover costs, etc.

henry

[rick rottet]

Yeah, I have a spare couch and plenty of frozen pizza. hehe

[Anthony Calfo]

cheers, Henry :)

I'd love to visit indeed. Perhaps we could share expenses with another club? I'm in St Louis and Chicago next year (Sept/June respectively):
http://www.readingtrees.com/meet_the_authors.htm

kindly,

Anthony :)

[rick rottet]

I recently put up a website as a subdomain of our local clubs website. It also shows the construction of the greenhouse.

http://www.prairiereef.cimaonline.us

[rick rottet]

Don't forget about IMAC, Henry and Anthony will both be speaking this year!!!

[melev]

Originally posted by rick rottet
I recently put up a website as a subdomain of our local clubs website. It also shows the construction of the greenhouse.

http://www.prairiereef.cimaonline.us

Wow, that was very very interesting. Thanks for sharing the link! I read almost everything you wrote in the 9 pages, but didn't see if you have any concerns about the plastic being torn by hail storms? Do you have them there? We do in Dallas / Ft Worth (Texas).

Looking forward to more updates as this project progresses. If you don't plan to post them here, would you be willing to PM me the correct thread?

[rick rottet]

Hey melev,
Thanks for the kind words and interest in this project.
I have seen you around the boards many times and have a great appreciation for the things you have done around RC.
Hail storms are rare up here but I suppose it would be a concern depending on the size of the hail and the wind at the time.
The original thread is in the first post of this thread. It is over in the CIMA forum under the same title.

[melev]

Excellent. Subscribing now!

[rick rottet]

Thanks again melev for your interest and contributions.

Anthony, I just couldn't say enough about the help and inspiration you have been. Maybe we can work out that side trip for you in June, before/after IMAC? I only live about two hours south of Chicago and the local club originates (sorta) another 45 minutes south. Anyway, hope to shake hands at IMAC.

[ggfish]

Wow, good luck buddy ,I can't wait to see some pics ,If you could put a pool under there and make it a reef pool i'll fly out,Best of Luck To you!

[rick rottet]

ggfish-Thanks. I have actually been discussing using my swimming pool (24' round 4' deep) as a cooling resevoir/loop for the prop tanks in the greenhouse. I have "told" my wife that when the kids grow and move away, I am turning the swimming pool into a reef. I was thinking a big greenhouse dome would be pretty neat over it.

As for seeing pics, there are two links farther up in this thread. One is my non-commercial subdomain of our local clubs website and the other is a thread here at Reef Central- lots of good discussion in that one.

[rick rottet]

It's getting close.
Two tanks are now completed. Anthony, I don't know if you visit this forum anymore but, we had talked at one time about wooden support structures being built around plastic tanks. Space constraints (and stubborness) made me rethink and try to build tanks that could be freestanding. Here are some pics of the first two. They are 7' x 2' x 2'. ~~210 gallons. Built from 1/4" pvc sheet. I used 1" angle pvc to reinforce all the joints, pvc square stock to make cross braces and put 1 1/2" stainless steel screws with 1 1/2" washers through the sides into the cross braces. There were a few design flaws and lots of experimentation along the way, but the final edition of first tank held water for five days before I drained it to add the overflow wall.

http://www.prairiereef.cimaonline.us/mini-100_0270.JPG

http://www.prairiereef.cimaonline.us/mini-100_0255.JPG

http://www.prairiereef.cimaonline.us/mini-100_0257.JPG

The remaining 19 tanks will have three submerged cross braces instead of two.

http://www.prairiereef.cimaonline.us/mini-100_0268.JPG

[melev]

I'm still worried about those connections at the top. Each of those points are pretty highly stressed, although I don't know the physics that others can factor for you.

http://www.melevsreef.com/rc/stress_points.jpg

Basically all the pressure along the linear length is on those three stress points where the cross pieces are glued and screwed. All the pressure is on something like 1.5" square inches at six specific locations, and up high where you don't have much material reinforcing the area. I can see how the tank is a tad wavy in one of your images.

If you were to run a strip of that half inch stock along the outer length (or the inner one for that matter) and glue it in place, you'll be helping that area's rigidity and the cross brace would reinforce it's larger surface area.

Think about this for a second. It is one thing to fill it up with water and watch for failure. It is another matter with day to day activities, leaning against it, reaching in and out, having LR topple over against it, someone bumping into it, or god forbid something fall against or on it. If you plan to make 20 or 21, they should be something reliable for a long time. Sure, things will happen and one will have to be repaired for some reason, but these really are too flimsy in my opinion. I had to build an 80g sump with 1/4" acrylic once, and it was tough maintaining shape and integrity. You have almost 3 times the volume, and it is 7' long. That is a lot of pressure in the center of each long panel.

Even a welded collar that goes around the tank and rests on the top would be ideal. It could be like angle iron, but only be 1" down, and 1/2" across (if the material was 1/4" steel). There would be no lip hanging in the tank, but the collar would give the unit more strength along the top, where you need it most. It would look like this:

__
|
|
|
|

[rick rottet]

In that pic, the tank does look a tad wavy. Part of it is the fact that I cut the center brace about 1/8" short (not on purpose) so the center is actually pulled inwards a little which makes the rest of the tank look bowed more than it actually is. IIRC, the bow is/was 3/8" at it's widest point when it was full. During the five days the tank was full, I did push and pull around on it (and not gently) to stress the tank as much as possible.
tschopp and I discussed the load on the screws a bit by PM and here are some excerpts.


quote:
--------------------------------------------------------------------------------

rick rottet wrote on 03/28/2005 11:27 PM:
Have you seen the latest pics of the pvc tank? Am I calculating the load on each screw correctly? (8.3 lbs/g X 210 g = 1743 total pounds / 10 screws = 174.3 pounds on each screw. IF the tank was full to the rim. Plus it would be spread a little because of the 1 1/2" washers. I just can't imagine 174 pounds pulling out an 1 1/2" long screw.
Allot of the guys are thinking I should put some more structure on the upper edge of the tank. My thoughts are...1) At some point, I get tired of doing mods/testing/experimenting/spending money and feel like I need to just go ahead and "run what I brung". 2) The main idea was to start with as cheap as possible and if that didn't work, to modify the design until it holds. The tank has been holding for about 60 hours now. If the tank seems viable, why go any further with unnecessary work and money.
Treeman has been saying that his tanks warped bad enough to make him go back and fix them by adding a 2" euro brace around the top rim of the tank. It took five months for his tanks to warp. He is in the Florida sun and has acrylic tanks. Know any info about the stability of acrylic vs. pvc? Any other thoughts?

(Answer from tschopp)
The force on the side panel comes from the water pressure. I get a total force on the side of 873 lb = 24" * 84" * 1/2 * 0.866 psi . Most of this force is held by the glue joint at the bottom. It is hard to guess the exact force on each screw. If the mid depth screws were not there I would say 3/4 on the glue joint and 1/4 on the screws (1/4 * 873 / 3 = 72 lb ea). If the top screws were not there I would say about 1/2 on the glue and 1/2 on the screws (218 lb ea). With both sets of screws the force should be less and concidering the glue on the vertical joints. Maybe 40lb on top screws and 120lb on mid screws, these numbers are heading into guessland pretty fast, but I think they are still close. I assume you are using something like a #6 screw. 120 lb sounds like a bit much for a single screw. I might consider going with 3 mid braces and 2 top braces. It looks like the mid braces are doing alot of work (even taking off some of the load from the bottom glue joint).

(As an insert here, I decided to use the three submerged braces he suggested instead of two but keep the three top braces, if for no other reason than asthetics.) Now back to tschopp.

I am familiar with the problem treeman described on his acrylic tanks. I have seen it myself. I put a sheet of 1/4 acrylic over my sump as a lid. after a while it started to warp and sink in the middle. The plastic was plenty thick to span a tub with no weight but its own, but it has a long term "plastic" property. That is why my sump has 2" pcv pipe over the acrylic. It is to support the acrylic. I am not sure if pvc has the same problem. I built a stand for some guages out of pvc sheet at work. I will look at it and see if it has any warping. It is a year or 2 old and should show if there will be a problem.


(A subsequent writing follows. This was after I told him I was using a #14 screw, not a #6. With that size screw, if the end profile of the 1/2" pvc square stock was divided to look like a tic-tac-toe playing field, the screw would take up the center square...more or less)


#14 sounds pretty strong.

I looked at the stand today. it is about 2' x 2' x 1/2". It was proped up on the wall at an angle. I did not see any warp to it. I think acrylic would have warped. I think you are right pcv is much more stable than acrylic.

End of PM excerpts.


tschopp did make a trip up here to pick up some barrels and looked at the tanks. His quote was, " I don't see why you wouldn't have something that will hold now".
I don't have the tank building experience that you have, but with the six braces, the tank is effectively six 2'4" tanks that are 1' tall instead of 7' x 2' x 2'...(well, sort of). I am going to run them. If I have to deal with something catastrophic later, then I'll have to deal with that at the time. I hope that doesn't sound curt or disrespectful because I don't mean it that way. I am just convinced that they will hold. I am sure your ideas would make the tank stronger, but I just think that if it is going to hold at this point, then that's good enough.

[melev]

No problem, Rick. As you probably surmised, I want you to succeed in this project.

Since you've only built two so far, it seems now would be the ideal time to beef up the weak spot with all the units when #1) assembly is easier, and #2) no livestock is involved.

You are there, seeing it in person. If you feel good about it, I'll defer to your judgement. :)

[Anthony Calfo]

outstanding to see your progress/pics shared my friend :)

I too am concerned about the stability of these tanks over time.

What may help these tanks is a four-sided capture (like anodized aluminum or powder coated enamel steel banding). This is what many of the aquaculture facilities do/use. Basically... angular reinforcement at the top and bottom (banding). FWIW :)

[rick rottet]

Actually, I mis-typed in that last post of mine when I said the six cross braces made the tanks effectively 2'4" X 1'. While that is true of the bottom half of the first tank with TWO submerged braces, the top of the first tank with three braces and the entire second tank with the six braces makes four sections 1' tall by 1'9" long. Not trying to make any point here, just correcting my math. /blushes