I love him too! He’ll always be my (not so) little guy. He’s 8 inches currently I got him when he was a baby around 3-4 inches. So in a year and a half he’s doubled in size and will probably double again lol.wait until he get 12" then say that again...haha love that little guy.
I personally think the stand is fine. it based off a tried and true design. once you add a skin it will strengthening it up even more.
that is build 10-20X better then the stands they sale at the box stores.
ask around your local area someone might have a utility pump and hose to help you leak test it. it's prob. fine but you never know. be a shame to wast the RODI water and salt to fine out.