There are some tips to get past Time Attack Mode for the corresponding achievement:
1) If all else fails, try try again--For the first couple of stages, there won't be enough fish on-screen to be able to get clear the stage, so keep on trying until you get past this initial hurdle.
2) Stay Low--For most stages past Stage 2 of the Andy stages, where will be oysters on the bottom of the ocean that will ocassionally open itself up, sometimes revealing a pearl and shut itself. Be sure to quickly grab the pearl thar is in the shell before it closes, especially the black peal, which increases your growth 5x as much as a regular white pearl.
3) Catch me if you can--Every once in a while, there will be a golden minnow that will go on-screen and quickly swim off screen before you know it. Eating this fish will guarantee you a growth level, regardless of how are away from the next growth checkpoint you are.
4) Go on a feeding frenzy!--In the later stages, there will be a red pirhana bubble that once eaten, it will eat all of the fish you are allowed to eat at the time in a flash. Use this to your advantage.
5) Later levels = bigger time bonuses---After you get past the inital hurdle, your amount of time that increases at the start of a new stage will be longer as you progress. Once you reach Stage 8 of the Orville stages, the game will add a whopping 5 minutes to the amount of time you have left, meaning you will pretty much clinched the achievement at around stage 3 of the Eddie stages.
That is all of the advice I can offer for now.