Hydrometer question...

[ScurdOfCychlidz]

So ive had my tank going for about a week...only thing in there is my sand and my salt water ( i hopefully get my rock tomorrow!!!)...but my salinity (sp) is too high...or gravity you might call it? (sry) its registering at 1.026. Will adding tap water (non-salted) help bring this down? I mean im assuming yes...its just i have added probably 2 gallons of regular water and that number has not moved!!

Thx for the advice!

 

[blorkiemom]

I don't think that's too high, esp. for a reef tank (alert: newbie giving advice). But adding RO/DI water should bring it down easily--it doesn't take much to adjust, I've found. If you've added a bunch of fresh water and the reading hasn't changed, maybe there's a problem with your hydrometer? A bubble stuck on the arm, maybe? That will mess up the reading. I hated mine and ditched it for a refractometer after a week and haven't looked back. Highly recommend it!

 

[indy]

How big is your tank? If it's 100+, 2 gallons won't bring it down much. If it's a 10g, then you've got a hydrometer problem if it didn't move after 2. But ya, remove tank water and add fresh to bring sg down. Save the water you remove in case you drop too low. Just go back and forth until its where you want it. 1.026 isn't super high, I usually recommend .023 to .025.

FWIW, salinity is the measure of salt in the water. SG is the measurement of the density of the water itself. Pure water (nothing but hydrogen and oxygen) has a SG of 1 and is the base measurement. Anything disolved into the water will raise the SG. Koolaid will raise SG but won't be much good in a SW aquarium Both scales will give you good measurements, but the #'s are not interchangeable, sg of 1.023 and salinity of 1.023 are huuuugely different things.

 

[Atari]

FWIW, NSW has a salinity of 35 ppt which is the equivalent of 1.026 SG. I would probably stick around 1.025 though to allow for some evaporation.

 

[malkore]

honestly, if you want an easier life, pay $45 for a refractometer. most hydrometers (the float type) are calibrated at 60degrees F. For every 10 degrees of temp increase, the reading has to be adjusted (it's like by .001, but I can't recall if you increase or decrease the reading).
I think the instant ocean brand of swing arm hydrometer is calibrated at 77 degress, but mine never gave the same reading, back to back, even making sure there were no bubbles on the arm.

but my refractometer is always right, because it measures salt content by how the water refracts light, which isn't skewed by slight temp changes.

 

[ScurdOfCychlidz]

ok thanks for all the advice...unfortunately i can't spend the extra $45 on a refractometer...

get this: wake up and test the water again today...(cuz live rock is comming tomorrow) the temp is 78 degrees and this time the hydrometer says its about 1.034...thats like a HUGE JUMP... do you think something is messed with this tool? Or my water is just out of control!? hah, thanks

 

[ClownMan]

Salt;

Sounds like you added to much salt .take out 1 gallon add 1 gallon fresh test salt do this until you hit 1.023 to 1.025

 

[malkore]

If it was 1.026 yesterday, and the day before, I think your 1.034 reading is wrong. You'd have to have a lot of evaporation to increase salinity that much.

I've only been in SW for a little while, but $45 isn't a big expenditure in a SW/reef setup. My 40gallon tank has wound up costing me well over $600 to get running, not counting fish.

 

[steve-s]

this time the hydrometer says its about 1.034...

Don't take offence to this but are you rinsing the hydrometer in fresh unsalinated water after each use? Salt build up will also hinder the readings.

Cheers
Steve

 

[EL Diablo]

IMO save the 45 bucks or so and get a Refractometer.
When I take a reading with 2 different Hydrometers they are always .02 off from
the Refrac reading. Bottom line: Hydro's are slightly off.
Not a device I really want to use to monitor my tank and make accurate adjustments with.

This is a fairly expensive hobby, if you have a tank up and running you already spent a ton on it. bring lunch from home for a few weeks and pick up the Refract

here it is onsale for 42.99
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=9957&Ne=40000&R=9502&N=2004+113410

 

[ScurdOfCychlidz]

hah, i do rinse it every day with the good ol arizona tap water...im thinking little bubbles sometimes get on the thing and it makes it way off...i tap it but sometimes the bubbles dont all float..grr

I get rock tomorrow..so we will see what it reads then.

 

[TygGer]

Or better yet! Use this link, $35.

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=11275&ref=2020&subref=AC

 

[ScurdOfCychlidz]

i checkd it again today...its normal..i think i had like 2 little bubbles that threw the hole thing off...thx for the links tho.