swing arm hydrometer possibly killing my inverts.

[TomCs]

ok ive had my tank going through the cycle for just over two weeks now. Everything's going well with my first algal blooms, amonia spike, coralpolyps, etc.
One thing that's worrying me is that my tank is open hooded and has a fairly constant, fast rate of vaportation. But i check with my hydrometer (i no, not extremely reliable) daily and the SG still sits at 1.024. i have a marker on the side of the aquarium to fill up to and when this first occurred and i even topped up with RO straight away. Coming bck to the tank later that day i checked the SG and it had dropped to 1.022. I no these things arent every reliable but arent they at least consistant? It should be pointed out im using natural sea water which i get at a constant 1.023-1.024 depending on the weather. Should i keep topping off with RO anyway? atm im not and going by what the hydrometer is telling me, which for now means that my SG hasn't moved from 1.024 since adding that fresh water.
Thanks for any help guys.

[HappySkittles]

do you dip it once and record what you get?
i dip it in maybe 10 times before i make any conclusions about the water. if i went on what it said the very first dip i would be SO wrong and probably kill everything. if it comes out the same various times i figure THAt must be the reading.

i also rinse it before and after i use it in the sink with fairly cool water.

also i think it reads differently based on the temperature.


i also believe swing arms cant be terribly inaccurate. how would people have been able to keep saltwater tanks with any success at all years ago?

[Bonneville08]

Make certain the hydrometer is pristine with no scale in it anywhere. soak it in white vinegar for an hour. Make certain there are no air bubbles on the float, they make a big difference. Dipping a few times shouldhelp with bubbles. A refractometer is better, but you know that already. Once you are in the ballpark, the biggest factor is to maintain a steady salinity by making regular additions of RO or DI water. If all you do is add fresh water for makeup, and use NSW for changes, your salinity should be just fine. I check salinity about every two weeks in the tank as a sanity check, other than that I use it to mix new seawater. Keep your salinity steady and don't sweat it.

[TomCs]

cool, thanks for the help guys, i do take multiple readings per day since my system is still stabalising. But i have to admit i dont wash it between readings. As far as bubbles i make curtain none of that gets into my masurements. i get a good 3cm (about 1/4inch) of evap per day and i get nothing??? i run with 4xT5 fixture and room temp as well as tank temp nothing out of the ordinary: room, about 20C and tank 26C (79F). If this sounds pritty normal then im a happy man, just waned to make sure i was paying enough attention. but again thanks for the help, being new to it all this site saves my sanity.

[Aquarist007]

I would suggest you invest in a refractometer. Much or accurate and less problematic for error. It is a wise investment for this hobby esp when you start to purchase fish and possible need to treat problems like ich.
Here is a link you might be interested in:
http://www.reefcentral.com/wp/?p=265

[Johnny C]

I have the same issue... DEF want to invest in the refractometer!

[808lazyd]

definitely make sure to clean it after every use this will help out alot