Hydrometer Vs. Refractometer

[wiszmaster]

I took some water samples of the tank, the tap, and the RO/Di down to boardroom yesterday .... to make sure the whole house RO was doing OK, and to make sure the RO/DI for the tank was doing its job as well .. everything checked out just fine.

Then while testing the tanks water the calcium was in the 150-200 range .. awefully low. tested the salinity .. and it showed as 1.019-1.020 ...

NICE! my hydrometer read 1.026 all day long on the same water.

OK - maybe error on rich's side.... i went home, unpacked my refractometer that arived by FedEx today ... tank water = 1.019


I've been bring the water up over the past 6 hours ... its now @ 1.026, and should probably not change ... maybe 1.025 .. the refugium still read @ 1.024 while tank & sump were @ 1.026



there are alot of refractometers on ebay for pretty cheap .. how good & acurate are they ? no idea.... but i've seen some up there for mid $20's to low $30's ....



ryan ... i know when i was down last time you mentioned that my calcium was a bit low as well, and we spoke about the salinity ... @ that point my hydrometer read 1.023 & i brought it up to 1.026 .. or so i thought ...according to it. i was probably @ about 1.015-1.017 back then ...

could that have been the reason for the tanks cloudyness, a die0off due to the low salinity level when i added the extra 90 gallons on sunday after installing the sump/fuge

[wiszmaster]

forgot to add that i brought the calcium up to about 400 or so as per my RedSea chem test ... did this with Purple Up

[Hobster]

These might help:

http://www.reefkeeping.com/issues/2004-06/rhf/index.php


This is a list of all articles, pick your posion.:)

http://archive.reefcentral.com/forums/showthread.php?s=&threadid=102605

[wiszmaster]

Thank You!

are you bringing everything else to rich as well?

[Hobster]

<a href=showthread.php?s=&postid=8524996#post8524996 target=_blank>Originally posted</a> by wiszmaster
Thank You!

are you bringing everything else to rich as well?

No, not if other folks want some things. The LFS here in the Cape wants some of them.

[coralfarmer84]

refractometers are the way to go from what I hear, however I have never used one, i use hydrometers at the store and at home and have never had a problem.

[alizarin]

In my experience :
- the typical kind with the floating arm are acurate if you're really careful not to get any micro bubbles making the arm float but it's difficult for me (and easy not to see the bubbles). I think they're dangerous to trust.
- the floating hydrometers are pretty acurate - the kind that are a thermometer that float in your tank) but they break easy. I had a puffer bite one in half once =(
- refractometers are pretty darned acurate (constant results). If you're lazy and get bubbles on the plate it can blur the results but it's easy to see there's a problem.

I think all refractometers are the same, some just have back lighting or slightly different materials. I bought a cheap one (40$? on ebay from hong kong I think) and would never go back to the other kind.