Help with Hydrometer

Hi all,

I am completely new to saltwater. I have a 10 gallon which has real ocean water, and I plan to continue to use ocean water for the time being, but I still need to figure out the salt level to account for evaporation and such.

I picked up an "instant ocean" hydrometer by Marineland labs(the cheap plastic looking thing that looks like a gas gauge). However, I found the instructions in the package to be absolutely awful, and I am not sure how to properly use it. Exactly how far do I fill it with water from the tank (if I fill it the whole way with water it maxes out the meter), but there is no bar to know how far I should fill it.

So, has anyone used this hydrometer, and if you have and suggestions that would be great.

Thanks,

-Adam

 

You have to submerge it in the tank and pick it up out of the water. Make sure no air bubbles are clinging to the swing arm, and that's your salinity or SG level.
Of course most would rather trust a calibrated refractometer, and it only uses an eyedropper and 3 drops of tank water, so more accurate and less mess.:thumb_up:

 

Just dip into the water and fill it up. The needle will do the rest. You may have to flick it a few times with your finger to get the needle to move. You have to account for temperature though. A "true" reading on those is based on water that is 60 degrees. For each 10 degrees rise, you subtract .001. So if your reading is 1.025 at 80 degrees, the real specific gravity in your system is 1.023. And I would take my sample from the middle of the tank, not just skimming the top.

Wash it out after each use with tap water so salt crystals don't mess with the needle.

That's about it. Have fun!!!!

 

Now THAT is what I want!!!!

 

1.030 is the highest it goes right on the hydrometer? and you are filling it up with tank water and it pegs it? (goes above the 1.030)? I think either you got a bad one(not real sure how, cause all they are is plastic) or the water where you've been getting it from is way over normal SG and you need to call a marine biologist LOL nah....rinse it out really good with fresh water, a few times and try it again. Try with fresh water too...should not more at all. If it's still that high take some water to your lfs and get them to check it with a refractometer....which btw are not that expensive and well worth the $$ to know exactly wacha got! I'd say if it turns out that the water's SG is that high, then you need to water it down with fresh(ro/di preferably) until you get to between 1.022 and 1.025


salinity and pH and they work great!
$39.98 plus shipping
Salinity Refractometer + pH Meter Tester Aquarium ATC - eBay (item 380045212976 end time Jul-17-08 06:27:00 PDT)

 

i would buy a refractometer if u are serious about the hobby and keeping your animals alive. I had quite a few of them pieces of garbage and u never know when they are gonna fail. I remember the days of slamming em on the table to get the damn bubbles off the arm so i could get an "accurate" reading. got one of these now


Milwaukee MR100ATC Refratometer with ATC

 

On sale at DFS (30% off) - Portable Refractometer

Really a "Must have" if you are serious about long term health of tank.

 

Hi, thanks for your answers, but I still have bad reading with my hydrometer.

I checked it with freshwater, and the the meter did not move. I put saltwater in it, and the meter is pretty much maxed out at 40 ppts, and 1.03 sg. Woa, that is pretty high.

Since I need to account for an 80 degree tank (not a 60 degree tank), I subtract .004, and I get 1.026 for my gravity. Is this correct math and logic?

On the meter, the "good range" for PPT is 28-32 (now is that for 60 degree water or 80 degree water... if you see my question). Does this "good range" on the meter represent the average aquarium, or the aquarium at 60 degrees?

I am not quite sure why the salt is so high. I have only had the tank setup up for a few days, and not too much has evaporated, and it was real ocean water in the first place??? Any ideas?

Thanks,

-Adam

 

I have two things, I had one of those and I recently bought a refractormeter. My hydrometer was actually very accurate. the key was that I had to knock off all of the bubbles to get an accurate reading. I thought that my hydrometer was calibrated for 78 F. So no subtraction was needed. When i got my refractometer and calibrated that, they showed almost the same number. maybe it is calibrated already. It sounds like you have some bubbles on your swing arm. Make sure there are none, even tiny bubbles can affect the reading to a large degree.

 

Just read a description of the instant ocean hydrometer and it says it is calibrated for temps. between 65 and 85 F