How to patch a hole in a plastic rainwater tank?

[s321]

I have a 5000 litre plastic rainwater tank where someone (not me) has cut a 100mm hole into the top of the tank. I'd like to patch the hole so that it's not letting leaves/mosquitos/etc in. I imagine that all I need to do is get something like a piece of plastic and silicone it around the hole, but I'm not sure what type of plastic I should be using. It would of course need to be able to withstand 24/7/365 outdoors under the hot sun.

Since it's on the top of the tank, above where the overflow pipe is, it does not need to hold any water pressure. It's purely to avoid dirt getting inside.

Can anyone suggest a good product to use?

[EricL]

Hello @s321 

One quick way to cover the hole is to get a Holman 150mm PVC DWV Push On Cap. Place a bead of silicone on the edge of the cap cover and place and centre it to the hole. Another option is to use a plastic basin such as the Ezy Storage 30cm 4L Round Plastic Basin. Do the same thing and place a bead of silicone on the top lip, turn it upside down and place it over the hole.

If you need further assistance, please let us know.

Eric