LFS water salinity

Simon Fraser · Mar 2, 2017

Hi all,
We're cycling our first marine aquarium & loving it.

Our aquarium is small (10g) so have been using pre-mixed water from our local LFS and have visited 3 differnt LFS's now and according to our hydrometer the water we are getting is close to 1.020 rather than the generally preferred 1.025.
Should I be expecting the pre-mixed water to be 1.025 or is it common practice to mix in marine salts to get it right?

Fishgeek88 · Mar 2, 2017

I would ask what they make theirs up to. When I use to run a store I would do 1.023...gave the most flexibility for people walking in. Also hydrometers can be inaccurate.

lariat8099 · Mar 2, 2017

1.023 to 1.025 Is a good range to shoot for.

Simon Fraser · Mar 2, 2017

Fishgeek88 said:
Also hydrometers can be inaccurate.

I think a refractometer is on my shopping list.
I asked the LFS I visit the most and they tested the water at 1.022. Still, my (new) hydrometer hardly rises above 1.020 piece of garbage!

glb · Mar 2, 2017

Fish store salt water is often a lower salinity. Definitely get a refractometer!

Simon Fraser · Mar 2, 2017

glb said:
Fish store salt water is often a lower salinity.

I assume the only way around this if I wanted to have a higher salinity is to get some marine salts and mix additional myself?

tgfitz1 · Mar 2, 2017

Simon Fraser said:
I assume the only way around this if I wanted to have a higher salinity is to get some marine salts and mix additional myself?

You can buy RO/DI water and mix the salt yourself like you've mentioned, or you could also top off the evaporated water in your system with salt water, increasing the salinity.

Simon Fraser · Mar 2, 2017

I have been topping off the evaporated water with salt water in the hope the salinity will climb, I will purchase a refractometer soon to keep a close eye on the levels.
For the small amount of water I need on a weekly basis I find that the couple of £ for a 25ltr drum from the LFS is good value for me currently, unless I find a good deal for salts that is!

sithrico · Mar 2, 2017

It's a bit of an investment to start but well worth it if your going to be in this hobby. Get yourself a RO/DI filter and mix salt yourself. With this system
Aquatic Life Twist-In 100 GPD 4-Stage RO/DI System you get the best without the footprint and it's more portable than normal systems. A little less on the pocket book as well. With what you need to make this system will work fine for you. Then you have two options hide it under a sink or store it in a closet. Plus, if you get out of the hobby you can still use it for drinking water. But, it like nutritionist say. Know what you put in your body. Same goes for water. Know what goes in your reef. You will be in control and be able to know what salt your using the parameters you like to keep it at so on and so on. Plus, in the end it will save you time and money and you can make it when you need it even when LFS are closed. Good luck and welcome to the hobby.

FishLover01 · Mar 2, 2017

Some LFS run salinity around 1.020 . It is sufficient to keep most all fish alive but they do it to save salt.

glb · Mar 2, 2017

sithrico said:
It's a bit of an investment to start but well worth it if your going to be in this hobby. Get yourself a RO/DI filter and mix salt yourself. With this system
Aquatic Life Twist-In 100 GPD 4-Stage RO/DI System you get the best without the footprint and it's more portable than normal systems. A little less on the pocket book as well. With what you need to make this system will work fine for you. Then you have two options hide it under a sink or store it in a closet. Plus, if you get out of the hobby you can still use it for drinking water. But, it like nutritionist say. Know what you put in your body. Same goes for water. Know what goes in your reef. You will be in control and be able to know what salt your using the parameters you like to keep it at so on and so on. Plus, in the end it will save you time and money and you can make it when you need it even when LFS are closed. Good luck and welcome to the hobby.

Agreed. It is so worth the money and it's so much nicer to be able to make water whenever you need it.

jeff williams · Mar 7, 2017

Fill your hydrometer with fresh water and check it. See if it read 1.000. Also after each use rinse it out and before each use fill it with tank water dump it out then refill and check it you will get better readings. And lastly after I fill it to read it I bang the crap out of it to dislodge micro bubbles that stick to the arm