salinity life or death? 29 Gallon Tank

Discussion in 'Water Parameters' started by fishaddiction, Dec 26, 2012.

  1. fishaddiction

    fishaddictionValued MemberMember

    I purchased a 29 bio cube and added only the lfs water and I figured I would test my hydrometer but when I tested it said the salinity was at 1.032 I have 1 red mushroom and was getting a clown and possibly 1 bubble tipped anemone is the salinity high if so how do fix it? When I tested it the water was very sandy (I put a bag to diffuse the amount of water hitting the sand) so would that have an effect. Also how long should the water stay and I put it in around 6 1/2 hours ago it is much clearer than before but its still hard to see the back and finally the red mushroom I put it in while there is still some sand in the water is it ok or should it be removed soon? I have lots of live rock and live sand nothing fake.
  2. Sturty

    SturtyValued MemberMember

    I imagine the only way to bring down the levels would be to remove some water and add fresh water (declorinated and the same temp as the tank water)
  3. OP

    fishaddictionValued MemberMember

    I thought that but is it safe also how much?
  4. Mike

    MikeFishloreAdmin Moderator Member

    What is the temperature of the water? You can bring down the salinity by removing saltwater and replacing it with freshwater. Hydrometers are not as accurate as refractometers and can be even more inaccurate if there are small bubbles on the swing arms. Flick or tap the sides of the hydrometer a couple of times to make sure there are no tiny bubbles on it. If the reading is still too high then slowly bring down the salinity by changing a gallon or two at a time, then retest.

    Shoot for 1.023 - 1.025
  5. ryanr

    ryanrModeratorModerator Member

    Take a breath :D

    First, is there live-stock (apart from the mushroom)? i.e. how desperate is the situation?
    Second, if the LFS is selling salt water, and that's what you've used, I would be extremely surprised if the SG was anything more than 1.026. Possibly 1.028 if they sell natural sea water (NSW can swing a little, but is generally pretty constant at 1.026)

    Cloudy water will certainly change the SG of water. SG is a basic measure of the weight of a liquid. The more that is in the water, the 'heavier' it will be, and thus potentially a higher SG reading.

    Do you have any water left that isn't in the tank? If so, test that. If it is still reading high, cross-check at the LFS. I think you'll find that 1.032 on your hydrometer may actually be 1.026 in actuality. Take your hydrometer to the LFS, ask to 'calibrate'/cross reference your hydrometer against there's, or a refractometer if possible. Then, as long as you know that 1.032 on yours is 1.026, just ensure that's where your tank sits. I know of a few where their hydrometer reads 1.019, but it is actually 1.025, they just keep it at 1.019 on theirs.

    Test against your own water (take a sample), and the stores water to be sure.

    Temperature can also play apart, SG is temperature dependant (hence Mike's question), IIRC, SG of 1.026 at 26C/79F [that could be wrong though, I measure salinity not SG]

    Now, if your tank is genuinely reading 1.032, here's the maths (sorry, I'll convert to metric, then back to gallons):
    IIRC, the 29 Bio Cube actually holds about 26G, less, say 1G for Live Rock displacement and sand, let's call it 25G.

    25G = 95L @ 1.032 is 42ppt, giving about 4kg's of salt.

    You want SG @ 1.025, or 33ppt, meaning you should have about 3.135kg of salt in there.

    At your current 1.032 (42ppt), you have 3.135kg in 74.6L

    Therefore, you want to replace approximately 20L with fresh (preferably RO/DI, RO, or distilled) water.

    In summary, you want to replace about 5.25G.

    Depending on live stock in the tank already, you may want to drain the 5.25G, and slowly (say 0.5G at a time, and re-check), over a few hours, start replacing water to prevent osmotic shock.
  6. OP

    fishaddictionValued MemberMember

    I only have the mushroom and I'm going back to the lfs today so Ill ask about a refractometer my temp. is 76 degrees (factory set) I will also test the water when it isn't sandy (still a cloudy tank) thanks for the advice :)