The Puffer Forum

At what point do's sciense or knowledge tell when water is brackish? 1.001? Looking forward to hear an answer.

Reagards Jantje

1.001-1.018

i wanted to give this a bump.

the reason is i live on a river mouth esterie. i was talking to a mate the other day about setting up a cold water marine tank with some local specie of seahorses. now he is a very knowledgeable marine biologist and i ask the simple question, can i just go down the beach and collect water for WC ?? in short he said no, so why not?? the answer he gave was simple i live on a brackish river mouth.

again asked it can't be i'm too close to the ocean, and the water is to high in salinity for it to be brackish. reply was, not always at low tide the water will be more fresh high tide more salt, with that said how can we then bracket it??

there certainly isn't any fresh water fish found there, or any fresh water plants it's a beach by all definition and full of saltwater life. but it would appear that at low tide there is a decrease in salinity.

I have to get some figures for you but i still find it hard to bracket some thing that changes twice a day surely it's better to keep a fluctuation in the tank? I know we have to form a happy medium in the aquarium rather than a complete reconstruction, but as the first post suggested who decided that that is correct or is it the highest/ lowest it reaches in any given "brackish fish" collection area??

Fish can certainly handle fluctuations in salinity. Problem is your bacteria, which breaks down the wastes in an enclosed system, cannot.

Some species of fish that we keep are predominantly fresh water but do better in an aquarium with a little salt, whether this is because of the higher mineral content provided by the marine salt or the fact that the fish lives closer to river mouths than other types of fresh water fish that we keep I don't know.

True brackish fish that we keep are Euryhaline and would benefit with daily fluctuations but as PP said, the tanks nitrifying bacteria wouldn't survive, so any fluctuations have to be done over weeks rather than hours.

You can collect and use seawater if you have a clean source. Many people do round my way. You just have to sit it in the dark for a couple of days? ( don't know why) then filter and test before adding. Most collect from a boat with a submersible pump as high tide approaches. I have added some natural sea water into the mix with my tank and my corals and pods have thanked me. Just don't go in blind, it has to be checked thoroughly