reefphilippines.com

here is a link for getting correct values for your hydrometer with regardds to the temperature of water tested.



if there are other links like this post nyo naman dito.

instructions for corrections on calibrating for temp

"Short form:Specific Gravity is temperature dependant. See the next table for a quick lookup of the recommended hydrometer readings. They are based upon our recommended S.G. of 1.025 at 60 degrees F.Degrees F. Hydrometer reading.50 1.0255
temp specific g
55 1.0252
60 1.0250
65 1.0246
70 1.0240
75 1.0233
80 1.0226
85 1.0218 (rather hot for most tanks)
90 1.0210 (very hot for most tanks)

In more detail:1.025 recommended for reef tanks. Note that virtually all hydrometers are calibrated for measurements at a temperature of 60 F. Included below is a short table of temperature adjustments. Add the value shown to your hydrometer reading to get an accurate reading.Degrees F. Correction50 -0.0005
55 -0.0002
60 0.0000
65 0.0004
70 0.0010
75 0.0017
80 0.0024
85 0.0032
90 0.0040

For example: If the hydrometer reads 1.0235 at 80F, the actual Specific Gravity is 1.0235 + 0.0024 = 1.0259Note: (Can anybody explain how they get the value for this instruction? mahina ako pagdating sa mga ganito eheheheheh) If your tank is between 75F and 80F, this means you should try and keep your Specific Gravity around 1.0230 to 1.0235.For all practical purposes, the scale is linear between data points, so you can simply extrapolate between table entries. For instance, 78F is 3/5 the distance between 75F and 80F; the difference in corrections is 0.0024-0.0017 = 0.0007. 3/5th of 0.0007 is 0.0004. Add the offset 0.0004 to the base value for 75F of 0.0017 and you get a correction value for 78F of 0.0021.It is fairly common in the literature to see references to salinity in terms of Parts Per Thousand (PPT). For salinities in the range we are interested in, the conversion formulas are:Salinity = 1.1 + 1300 * (Temperature corrected Specific Gravity - 0.999)
Temperature corrected Specific Gravity = ((Salinity - 1.1) / 1300) + 0.999;Here is a short table of some common values:Salinity Specific Gravity

20 PPT 1.0135
25 PPT 1.0174
30 PPT 1.0212
35 PPT 1.0251 * Typical Ocean Value *
40 PPT 1.0289"

This URL may help - http://www.dynamicaqua.com/salinity.html

Shows all the variations of tools that can be used to monitor salinity levels

Fellow reefers, help... anyone?

Up to now, I still don't know if the salinity level I'm trying to hit is too much or too low because of the high discrepancy from zero (0) when measuring plain freshwater.

Btw, I took the meausrement even after the adjustment as described in the table.

solution: buy a refractometer.. heheh!
kahit ako bro, parang best guess na rin yung salinity ko..

sir ask ko lang where to buy cheaper refractometer i used floating type o kac eh the one that has thermometer at the bottom po. nasa 1.018 to 1.020 nasa at about 80f po yung reading nya tama na po ba yun o maxado pa matabang? cylce stage pa lang po ako ngaun with crush corals lang po and overhead filters thnks po happy reefing sa lahat^^

Bro, you can but it here look at your BUY and Sell section Aquarium Related, they are selling good equipments. You can go to catrimar. For you salinity, it is just fine but it is low in salinity, if you wish to keep corals you at least have a 1.022-24 salinity levels at 22-30 only at the maximum. if you got it 32 degrees you coral starts to die bro.