Hydrometer or Refractometer???

[sophia101]

Hello Everyone,
I am a "newbie" to this marine aquarium keeping hobby and i have a 65g marine aquarium with nothing in it yet. I am thinking of starting when i get back from vacation...i was wondering, i just bought a hydrometer :( but i heard they are not as accurate as a refractometer and i really need some help as to what i should do...is a hydrometer o.k????? I really dont want to risk hurting anything that will be in my tank :( PLEASE HELP!!!! Could i start out with a hydrometer and then switch to a refractometer??

[kau_cinta_ku]

don't much matter IMO if they are accurate or not. it is more or less if it changes on you. if you have a hydrometer make sure to clean it out with rodi or ro water after each use. if you don't then particals can catch on it and give a false reading. but first you will want to calibrate it so you know exactly what it is reading from the start. here is some good reading on how to do that.

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

so in otherwards if you can keep the salt level the same with a hydrometer then you will be fine. you just don't want it to change much when doing water changes. and try to keep it around 1.025

also another way would be to find someone with a refractometer and let you test their water with your hydrometer to find out how much it is off.

[mhurley]

IMO, spend he $40 and but a refrac. If you are starting out, you might as well start out accurate. You'll find many many threads on here of people that switch from a hydrometer to a refrac and were amazed at how off the hydro was.

The above post is mostly accurate in that it is more about stability rather than hitting a specific number. However, the assumption that is making is that the hydro reads the same value each time, and IME, they do not.

I consider it a core piece of important equipment (like an RO unit, good skimmer, good test kits..etc).

[sophia101]

where is the best place to get an accurate inexpensive refractometer? Please let me know...thanks.

-Sophia

[Travis L. Stevens]

As mentioned above, get the refractometer ASAP. You might be able to get away with using a professional grade glass hydrometer with special care, but I'm sure they cost just as much as a refractometer. To better understand why to get a refractometer, here is an example. A local reefer and I were discussing tanks and such and I was over there helping him with his tank and doing a few tests with my test kits for double checking and such. I went ahead and brought my refractometer for the little pipette. It turns out that he uses one of the plastic hydrometers. So, I decided to check it for him remembering my past encounter with the first time I tested my fresh new 1.023 saltwater tested with a refractometer and came home with a hydrometer reading of 1.032. He had told me that when he checked his water it was reading 1.028 (long story, don't ask) and when I tested it with my refractometer it was 1.033! That should just tell you how far off hydrometers can read.

[sophia101]

Wow! Thats not good at all :( I willl definietly look into getting a refractometer, thanks! Has anyone had good luck with a hydrometer (the instant ocean plastic hydrometer)?? Thanks again!

-Sophia

[Travis L. Stevens]

Personally, no. But there are people that are the exception. They also usually take extreme care with their hydrometer as well. But the risk, in my opinion, is too great to have a plastic hydrometer around. You might be able to get away with it if you have someone test your water with a refractometer and you test it with the hydrometer and just remember the possible difference until you can get your own refratometer. For example, your hydrometer might be 3.5 "points" off of accuracy. Therefore, your hydrometer needs to read 1.0285 for the water to actually be 1.025.

[E-A-G-L-E-S]

sophia......ygpm

[Gobie]

I have used the same cheep plastic swing type hydrometer for years, no problems. Aquarium Systems SeaTest.

[Inferno]

I just switched from a glass hyrdrometer to a refractometer. My hyrdrometer was off by 0.003 even though i cleaned it well each time. When i got it new i compared it to a refractometer and it was only off by 0.001 so it got worse with time. IMO the refractometer is worth the extra money just for the convenience and speed and auto temperature compensation.

[Travis L. Stevens]

Originally posted by Inferno
I just switched from a glass hyrdrometer to a refractometer. My hyrdrometer was off by 0.003 even though i cleaned it well each time. When i got it new i compared it to a refractometer and it was only off by 0.001 so it got worse with time. IMO the refractometer is worth the extra money just for the convenience and speed and auto temperature compensation.

Plus, you can recalibrate it. I don't think you can do that with glass or plastic hydrometers

[markrovner]

Plus which, Marine Depot has one for like $40!

[areze]

Im using a cheap plastic hydrometer. fish havent spit at me yet. but Id bet a hundred bucks its way off, its got algea and crap on it since its supposed to be kept in the tank.... refractometer is on my xmas list.

once I have a refractometer Ill keep the hydrometer sitting in the sump. much like those "first alert" ammonia monitors, I wouldnt trust it for important readings, but atleast when I can kinda calibrate the hydrometer it will tell me that Im in the range, if its way off, I pull out the refractometer and fine tune.

[RokleM]

I just find it amazing that people spend thousands of dollars on their tank, but when it comes to spending $40 instead of $10-20 on what I see to be a vital investment it's somehow a huge struggle.

But... maybe that's just me being a silly newbie ;)

FYI, not commenting on people in this thread specifically. You see this same reoccurring theme throughout the forums here on this topic.

[masterswimmer]

A refractometer is a vital piece of equipment IMO. No different than a skimmer, lighting or salt.

If you have even a small amount of bubbles or even a bubble in your hydrometer your reading will be off. Just way too many variables to mess with.

Like RokleM said, you're spending ungodly amounts on a biosystem to maintain delicate creatures, why skimp for the difference of about $30.

Off my soapbox.........JM $.02,

Russ

[old salty]

If nothing else, a refractometer allows simplicity in checking salinity. I have my main tank, QT, and pre-mixed SW. That's three readings I need to keep up on. A hydrometer gets messy, and after you dip it in water, you need to put it on a flat surface. This surface is gonna get salt water on it. More cleaning for you!! A refractometer makes checking salinity quick and easy with very little mess.

[Inferno]

old salty,
you got it right. it makes things simple having a refractometer so your more likely to check it more often. I definately check mine more frequently now that i have once since all you need is a couple drops of water.

[fishboy1]

My hydrometer was the same as my refractometer but I still wouldn,t go back to the hydrometer read to many horror stories Plus if you ever have to use hyposalinity you need to be very accurate.

[BBoley24]

of course the refractometer is going to be better... but if you cant afford one right now... get a coralife deep six plastic 7 dollar hydrometer... then switch... i went through 4 hydrometers with in 3 months... this one seems to work the best for me...

[RokleM]

Originally posted by BBoley24
... but if you cant afford one right now...
Then get all your stuff in the for sale forum, as this device costs less than your gas for a couple of weeks. If you're that strapped for cash, do your living creatures a favor and get out while you (and they) still can.

Originally posted by BBoley24
i went through 4 hydrometers with in 3 months...
Or... You could have bought one refractometer.


Ok... I'm off my soapbox for the rest of this thread.:)

[stingers81]

Originally posted by RokleM
I just find it amazing that people spend thousands of dollars on their tank, but when it comes to spending $40 instead of $10-20 on what I see to be a vital investment it's somehow a huge struggle.

But... maybe that's just me being a silly newbie ;)

FYI, not commenting on people in this thread specifically. You see this same reoccurring theme throughout the forums here on this topic.


if you can save $20 here and there it adds up....

[brad23]

Marine depot has a refracto for $35 until the end of Sunday.