# Cutting a HOB filter slot in the top of an acrylic aquarium



## pkut (Feb 3, 2005)

I have a 100 gallon acrylic aquarium that I want to run an Aquaclear 110 HOB filter on. The aquarium doesn't have an access slot in the top of it to accept the Aquaclear 110 filter. What are the best hand tools to use to cut a slot shaped hole in the top of this aquarium? Thanks for any input.


----------



## JALOOS (Sep 6, 2008)

I wouls suggest a drill to start a hole and a hacksaw blade or fine tooth saw of some sort to make the cuts. Be sure however that the parts you are removing are not there for any type of structural integrity or support.


----------



## pkut (Feb 3, 2005)

Thank you for your help. I thought about going the same route. I figured that if I put some masking tape on the surface of the acrylic, marked the four corners of where I want the slot to end and then drilled small holes at those points, that would give me a start. I can start out with small holes and slowly increase their size with larger drill bit sizes. I want to minimize heat build up.
At this point, I can use a fine toothed saw blade as you suggest and slowly cut the connections between the four holes. I will perform these cuts by hand to minimize heat build up also. 
I understand what you are saying about compromising the structural integrity of the aquarium. I intend to cut this opening at least an inch away from where the back and top pieces of acrylic sheet meet.


----------



## Mcdaphnia (Dec 16, 2003)

The problem you are likely to encounter is, because acrylic is much more flexible than glass, it is very likely to bow out once a slot is made in the top brace. The bulge is likely to twist against the filter until it breaks either the hanger part of the filter, or the filter box. Sooner rather than later, the bulge and stress points on either side of the slot are likely to cause cracks in the acrylic.


----------



## BinaryWhisper (May 5, 2006)

I know you came looking for advice on how to do it vs. whether to do it but...well don't do that. At best it will weaken your tank and devalue it greatly and at worst it will go wrong and wreck the tank.

All so you can hang an ugly arse HOB on a nice tank?


----------



## AfricanMike (Dec 15, 2006)

This wouldn't happen to be a tank from glasscages.com would it?


----------



## pkut (Feb 3, 2005)

This is a SeaClear Acrylic 100 gallon aquarium that is 5 feet long. I have an 85 gallon acrylic aquarium that I purchased new in 1975. It is also 5 feet long like the 100 gallon SeaClear.

The 85 gallon has two HOB filter slots cut in the top support sheet (it came this way as a new aquarium). They are about one inch in from the back of the aquarium and are 11 1/4 inches long by 1 3/8 inches wide. This 85 gallon acrylic aquarium is constructed from 1/4 inch thick acrylic sheet. It's as good as the day that I bought it new and has been set up for at least 25 of it's 34 year history.

This is the reason that I thought about adding these HOB filter slots to the SeaClear 100 gallon acrylic aquarium. I believe that the key here is to make sure that the slot in the top sheet is not too close to the back of the aquarium. If it is, you will then have flexing problems when the aquarium is full of water.


----------



## KaiserSousay (Nov 2, 2008)

> bought it new and has been set up for at least 25 of it's 34 year history


Both tanks being equal, would seem to not be a problem. 
A call to seaclear wouldn`t hurt. 
Seems to me, things that were made as little as 5 years ago are of better quality then now. 
They don`t make them like they used too, is sadly true. 
Good luck


----------



## pkut (Feb 3, 2005)

Thanks for your input John. I know what you mean about present day quality on a lot of things. There seems to be a lot of throw away and planned obsolescence items these days.


----------



## KaiserSousay (Nov 2, 2008)

Been keeping my ears cocked to the north..didn`t hear a yell, followed by a splashing sound :lol: 
Did you cut it :-?


----------

