the plan is to spot some silicone along the bottom to cure before panel arrives, then seal generously everywhere inside the frame, push the front panel up to the frame then we were gonna drill it and use some stainless screws all round, sealant through the screw holes. i'm gonna use a sealant called CT1, its V.O.C. free and i use it at work a lot, seals and bonds all plastics etc. its working fine in the filter. yep went for acrylic, 25mm thick. thinking now off dropping the water level about a foot so i can plant it out with orchids and other epiphytes, on some more oak.