Surfermike hey vik, I have had a really big bumblebee that grew to 5 and half pounds. What really matters for them is dissolved calcium. Crushed coral. Keep pH 8.4-8.6. Brackish is fine. Salt as they get bigger is better say around 2 foot mark. You will do really well with urs. I am about to buy another after my move and raise him to huge size hopefulmally.