You, my dear, are a wealth of information! Thank you!You don't need to do a water change every day.
If you put a line on the tank (with a permanent marker) where the water level is, you can simply add freshwater to top up any evaporation. Just add fresh water to get the level back up to the line. This means you won't need a hydrometer or refractometer straight away.
If you go to the beach at night when it's calm, shine a torch on the water in one spot and leave it there for a few minutes and lots of plankton will gather under the light. Then scoop them up and put them in the tank. You get all sorts of cool stuff doing that.
You can also buy light floating plankton traps from Ebay. They float under the surface and have a light on them. The light attracts the plankton and it goes into a plastic holding container. Then you pick it up and put the plankton into a bucket.
Ah, that is the caveat. During low tide it can go out about 100 feet, and impossible to walk on the soft sand (muck). As it is, we had a massive hail storm this afternoon that left about 1" of ice on the ground. Visibility is going to be shot tomorrowYou don't have to look for plankton on a high tide. If the water is more than 2 feet deep, you can get plankton any night.
gotchaAh, that is the caveat. During low tide it can go out about 100 feet, and impossible to walk on the soft sand (muck).
Is that the one south of Freo? If so, I believe I've been there. A very nice place indeed!Woodman's Point and there was a nice calm bay there. You could walk out 100meters and the water was only 2-3 feet all the way out. It had nice sea grasses growing there and all sorts of wonderful things living in the sea grass. It has nice white sandy beaches and white sand going out to sea.