Large Acrylic Tank Questions

[griss]

Hi all,

We moved into a new house in July and I am in the process of trying to determine the dimensions of my next tank. My tank will be in my basement and since I don't have a walk out basement, I will need to negotiate the tank down a set of fairly narrow stairs with a 90 degree turn at the bottom.

Because of the weight of a large glass tank, I decided I do not want to risk trying to get a glass tank down the steps. I just don't think it will be humanly possible to get enough people on the stairs to safely get a large glass tank down them. Therefore, I have decided to go with acrylic.

I want to have a tank in the 450 gallon range. I would also like to have minimal or preferably no bracing on the top of the tank. The reason for this is ease of maintenance, high light penetration (as I will keep primarily Acroporas and Tridacnas) and lower risk of the intense lighting cracking the braces. I would also like to have the tank viewable on three sides with the overflow on the fourth side against the wall to my future fish room. The tank sizes I am considering are as follows.

5' x 5' x 30" - 467 gallons
6' x 5' x 24" - 448 gallons
6' x 4' x 30" - 448 gallons

Keep in mind, I have never owned an acrylic tank or seen an acrylic tank larger than 200 gallons in person. So I am a little leery of some of the quotes I have gotten from some vendors.

Of the 6 vendors who have responded to me, 5 of them have stated they would use 3/4" acrylic with 4-6" perimeter bracing and a 12" center brace to build these tanks. The prices quoted range from $1900 to $3600.

My questions are:

1. With this thickness of acrylic and the bracing described, how much bowing will I see from the sides of the tank?

2. How much visual distortion can I expect from this bowing?

The 6th vendor said that they would use 1.25" acrylic for these tanks with no bracing at all. However, the price quote on this tank was over $4500, which is out of my budget.

Any insight or input would be greatly appreciated.

TIA,

George

[AQUATICADDICTION]

THE 6X5X24 sounds like the winner for your situation and budget. water as we know is heavy stuff. and the amount of pressure it can create is considerable. your sixth vendor with the quote the had the 1.25" . Sounds like he knows what it would take esp Without any bracing . but the 6x5x24 not only will allow ease of maintenence but allow a more intense light for all those acros making for some really happy little clams ;).

[KenT]

I had a 500 gal. that was 48" front to back. A little too deep in my opinion. I now have a 535 that is 40" deep and is easier to aquascape and reach things in the back. 36" is plenty deep enough and probably ideal.

My old 500 was 96"x48x24" 1/2" acrylic. It bowed a lot and definately not tall enough for good viewability. Soft corals quickly outgrew it.

My current 535 is 96"x40"x32" 1" acrylic, and can not see any bowing.

[AuroraDave]

KenT--I few questions about your current tank.
How easy/difficult is it to aquascape and reach things on the bottom or in the back? Do you lay on the top of the tank?
Do you have a DSB or barebottom?
If DSB any trouble with scratches? I use a magnet but I am always scared to death when I get near the sand. I try to use a long-handled scraper for those areas, but that doesnt work well with coraline.
What do you do when you drop a frag or need to reach something to move it? Some type of tongs?
Thanks

[KenT]

Yes, I lay on top of the tank to reach the bottom, burn myself on the lights, and get my face wet. To aquascape and move things around I have to turn off all the pumps to be able to look into the tank from above. I too use a long handled acrylic pad to clean the algae off. It is a PIA! Yes, I have scratched the acrylic with the magnet from getting to close to the sand, which is only around 2" deep.

I love the tank though, and wouldn't have it any other way!!!!!

[AuroraDave]

Thanks Ken
I've found that its best to use the magnet more than less for if you wait too long and coraline grows then your work has really begun

[kevinpo]

Hi George,
I would recommend the 6'x4'x30". You can reach to the center if you have access from both sides. IMO 30" is the perfect depth. My tank is 33.5" and is just a little too deep (and I have long arms). I used 1" acrylic for the front and back and 3/4" on the ends and top with 1/2" on the bottom. No bow to be seen. For a 30" high tank you can use 3/4" OK but I don't know if you go without a center brace or two. With a 6' long tank you can go with three halides spaced evenly then you could have the top braces spaced so they fall between the halides (this is what I did). With a 48" width you can use 36" long reflectors mounted perpendicular to the 6' face and cover the whole 48" width with one 400W halide and not have too much light fall on the front and back acrylic tank viewing panels (reduces cleaning).
IMO the best stand height is 36" ( I have tried 32" and 40").

I have a little distortion from the 1" acrylic as you look at object in the tank at an angle but not looking through the 3/4" panel.

HTH,
Kevin
PS: You can come over and look at my setup anytime (you won't leave empty handed :D )

[Nanook]

You could just get some 1/8" plexiglass from the hardware store and make a small 15 gallon tank, maybe a 6"x4"x4" tank? I think I would look for the materials you need in glass, then pay someone to come over and make that tank. If nothing else, we could build the damn thing together. That way you can get the size you want and not have to deal with acrylic issues. Just a thought.


Nook

[Salt-Reefer]

Originally posted by KenT
Yes, I lay on top of the tank to reach the bottom, burn myself on the lights, and get my face wet. To aquascape and move things around I have to turn off all the pumps to be able to look into the tank from above. I too use a long handled acrylic pad to clean the algae off. It is a PIA! Yes, I have scratched the acrylic with the magnet from getting to close to the sand, which is only around 2" deep.

I love the tank though, and wouldn't have it any other way!!!!!

You say you can lay on top of your tank, how thick is the top peice of acrylic?
Thats what I wanted to be able to do for mine but my top peice is 1/2 acrylic and I'm afraid that it cant hold my weight apprx (230lbs). Maybe if i lay a board where I lay it will help distribute the weight a little more.

Steve

P.s. Mine is 96lx40wx30d

[nematode]

Griss,
The tanks at tropics - what ever its called now- are 4 x 8 (perhaps only 6) I think, but not 30 deep just 24. call and ask. It might be worth a trip to look at them.

I have a 8 foot x 36 x 21 inch tank I made to replace a 30" x 48"" x 50" cube. ( these are wood and glass tanks).
I found that a 48" deep tank was quite difficult to aquascape when it was 30" deep. I am only 5" 7" and I almost had to dive in to deal with the cube tank.
3" of depth makes it much easier to reach thing. I'd very much hesitate making something 6 x 5 feet cause it would be very hard to reach things.

I also find that 8 feet of width is dramatically different from 6 feet. my 8 foot x 3 ' has the 'feel of a little ocean', while my 125 6' x 18" still feels like a box.

Lastly you might talk with gary at clayton pet. He built his tanks ( which have no lip at all). He might have a good feel for how thick the acrylic would need to be on a set up of 6 x 4 x 30 without any lip. I think the clayton pet tanks are 6 feet x 3 feet x 20" and I don't think they bow much at all.

[griss]

Originally posted by kevinpo
PS: You can come over and look at my setup anytime (you won't leave empty handed :D )
Thanks Kevin, but I don't think I'll be in your neck of the woods anytime soon:( In fact, I have not travelled for business since April:)

[griss]

Originally posted by nematode
Griss,
The tanks at tropics - what ever its called now- are 4 x 8 (perhaps only 6) I think, but not 30 deep just 24. call and ask. It might be worth a trip to look at them.

I have a 8 foot x 36 x 21 inch tank I made to replace a 30" x 48"" x 50" cube. ( these are wood and glass tanks).
I found that a 48" deep tank was quite difficult to aquascape when it was 30" deep. I am only 5" 7" and I almost had to dive in to deal with the cube tank.
3" of depth makes it much easier to reach thing. I'd very much hesitate making something 6 x 5 feet cause it would be very hard to reach things.

I also find that 8 feet of width is dramatically different from 6 feet. my 8 foot x 3 ' has the 'feel of a little ocean', while my 125 6' x 18" still feels like a box.

Lastly you might talk with gary at clayton pet. He built his tanks ( which have no lip at all). He might have a good feel for how thick the acrylic would need to be on a set up of 6 x 4 x 30 without any lip. I think the clayton pet tanks are 6 feet x 3 feet x 20" and I don't think they bow much at all.
I spoke with Jan at Clayton and asked her if Gary was building tanks for people. She replied that he is not. Actually, I was hoping he would, because I really like the job he did on their tanks.

I'll check with Tropics as well to see if they can build a tank for me.

George

[nematode]

Griss,
I think the tropics tanks are commericially built. but they will give you an idea of how much bowing you'll get.

[griss]

Originally posted by nematode
Griss,
I think the tropics tanks are commericially built. but they will give you an idea of how much bowing you'll get.
Thanks. Nanook spoke to Brad at Tropics when he was there last time and Brad told him he has a guy that builds tanks. Since Gary can't build me one, I'll try talking to Brad's builder.

George