Salinity Question

[fuzzydwarfs]

This is a 2 part question really...

firstly...Ive been testing the salinity up and down the coast here and its all at 1.030, so my question is, why do our tanks have to be around the 1.025 mark...

second question...which is better/easier...seawater or freshwater with the additives...is the freshwater (with the additives) easier to maintain (alk, pH, salinity, carb hard, calcium etc)...

I'm using seawater which the Aquarium I get it from gets from 5km off the coast...I seem to be spending half my time TRYING to get the salinity down from the 1.030 mark...would there be less algae probs etc NOT using real seawater...or is it all much of a muchness...

does this make sense to anyone...

cheers...
Joanne...

 

[rk58]

I'm new to salt water, but have tried to read as much as possible to get an idea of what is involved. Just from what I've read, it seems that the freshwater approach with added salts is the more common approach (obviously due to access, easier to do at home, etc.). Some of the things I've read, suggest that doing your own mixing is a little safer, also (pollutants, unwanted critters in the seawater). I'm thinking even 5 miles out, there are still things floating in that water that are washing in off the coast. At least with mixing your own, you have more control on the salinity. I make up 3-4 gallons ever week in a dedicated container ( I have a small tank, so 2-3 gallons are used for my water changes). I use a couple of gallons for the change, usually use some during the week to keep the level up in the tank and have a little left over for rinsing filter media during the change. I keep an air stone and heater in it, while it's "cooking". I mix it up initially a little weak, let it perculate for a day, check it and add more salt as needed to get it where I want it. If it's too high, add freshwater. I've also read that real seawater dies quicker than the mixes. I'm pretty lucky, that my tapwater is good. Haven't had to do much to it, in order to bring it inline. Hopefully this helped a little, again I'm no expert, just like to read a lot.

 

[Germanman]

the oceans salinity is all around 36ppm and the specific gravity is almost always 1.026 ive never got a reading so hight in the ocean and being a marine biologist ive been taught and observed that the oceans specific gravity is almost universally at 26. what kind of hydromiter are you using? as for the salinity lownees its for fish helth but i disagree with it, i keep my tank at 25. as for the synthetic vs sea water. sea water is more benificial but if done and cured improperly can cause great harm an an aquarium. id stick to RO water with the synethetic sea mix...instant ocean reef crystals is the best in my opinion. and ive used all but 2 of the salts out on the market.

 

[rayjay]

Specific gravity of your tank water rises as evaporation occurs on a continual basis. That's why you should be topping up your tank to the same level each day with RO/DI water or limewater if you need to keep calcium and alk maintained.
If the water is high s.g. when you get it, it's most likely that the LFS doesn't top up so you actually get a better deal (more water) by having to add water to brine the s.g. down.
If you use a commercial salt mix, don't use additives unless you find by testing that what you are adding is too low.
Some feel that you need additives to treated water before mixing, but I think most find that what is in the salt mix is sufficient once mixed and aerated.
If afterwards you find calcium or alk or magnesium low, you can adjust accordingly.
i.e. I add calcium and magnesium to my I.O. mix because testing has always shown I.O. to be a bit light for these chems.