Im looking at buying a 3 tank circulating system (no idea what it would be called) but two out of the 3 tanks are cracked is it possible (easy) to fix cracks or would i need to replace the glass?

You can silicone A bit of glass over it like this:

See at the bottom where those extra bits of glass are.

Being on the side would the water pressure be too much?

Um,I'm not sure.

Better off replacing any cracked glass than patching it.

Better off replacing any cracked glass than patching it.

I know it'll be weakened but if done correctly could it work?

Being on the side would the water pressure be too much?

I would think so. on the bottom there is very little real pressure on a fully supported tank

Anyone know where to order aquarium glass and how much would it cost? One pane is 4 feet by 1.5 feet and the other is 1 by 1.5 (roughly )

Anyone know where to order aquarium glass ?One pane is 4 feet by 1.5 feet and the other is 1 by 1.5 (roughly )

Your local glazier should have glass that will suit your needs.

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If you haven't already bought it then I wouldn't bother. Glass on the sides needs to be replaced and if you can't do it yourself it will cost more or as much in labour and replacement glass than it will to buy a new tank.

I havent bought it yet but my dad is an engineer so he could do it for me, it comes with a sump and chiller as well. Not sure how much it will cost yet though.... I'll see how much they decide on first....

FYI as I am not sure how experienced you are in fish keeping and buying equipment - tanks with cracks sell for very little, particularly with cracks in the side. They are often given away for free.

You could just keep on the look out for two cheap tanks that aren't cracked.

But there are three and a chiller, if i can afford it and transport im gonna get it!