Please Help Acrylic Tank Question

[bigjames1300r]

I am upgrading from a glass 55 to a 90 gallon Clarity Plus Acrylic tank and the two holes in the top of the new tank seem to be quite small. They are a few inches narrower than my light strip and I am concerned that will affect the performance of my lights as well as possibly create heat issues, so I am considering cutting the holes to make them wider. So my questions are: Is the light going first through the acrylic then into the tank going to significantly reduce the PAR reaching the tank and will opening the holes, but leaving the center brace going to significantly weaken the tank??

Any and all help wil be greatly appreciated.

James

[ErikS]

opening the holes, but leaving the center brace going to significantly weaken the tank??

It can but it depends on many factors. Thickness of the sides & top, structure of the top brace, etc.

 

I would not do it w/o consulting with someone like NAGA, an expert in acylic.

 

Off the cuff answer it that's it's not possible - makers like Calrity Plus use minimal materials & push the design closer to the limit = the holes are as large as they can be while maintaining the structural integrity.

 

Note: this is not a bad thing, glass makers like AGA do the same. The tank will work very well with the design they use.

 

Given the tranparancy of acrylic you won't loose much light........but as it gets covered with salt creep & splash you will = frequent cleanings to maximize light.

 

You can have heat issues, that being putting hot lights close to the top = top melts & tank fails.

[bigjames1300r]

Erik,

Thanks for the response. Your answer pretty much reinforces what I thought. The holes just seem to be so darn small. It seems as if I were to open them up like an inch all the way around that it would not weaken the tank much, but i am sure you know way more than I do. They are only 8 inches wide and my lights are about 12 inches, so I guess I will not lose that much light.

[ErikS]

but i am sure you know way more than I do.

Doubtful Just hobbiest experience, building a few non-structural things. Always better to be safe than sorry.

[NAGA]

I get hit with this question all of the time.

 

 

Light efficiency issues;

 

as Erik previously mentioned it depends on a couple of things but, where the big loss comes from is how often you clean your top from salt spray. Normally you'd lose 15% to 20% through the top with 1/2" material from what I have read. More if you let any build up happen. This is why when I build tanks for people I specifically ask them these questions and build the tank accordingly. If I remember correctly Erik has a 1" top on his 120g but, no center brace.

 

Weakening issues:

 

If you call Clarity they are going to tell you not to do it. It will void the warranty and with the minimum thickness they use on their tanks it would probably not be a wise decision. I have done things for people where we open up a tank from Clarity or Tenecor but, also add acrylic to the top to reinforce any that may have been weakened. There are never any guarantees with that though.

 

I always encourage people if they are planning to get a acrylic tank to have one custom made for what they need exactly. As expensive as this hobby his it pays to get something exactly what you need. The big acrylic tank builders will do it you just have to ask. If you want to save a few bucks certainly you can buy one right off the shelf that is pretty universal for just about any application. It is a beautiful think though to get one just the way you want it though.

 

hth

 

Jeff