Hyrdometer to use???

[BCReefer]

I need a new hydrometer as the old one feel apart and then landed in the toilet. I just have the cheap $20.00 plastic version. I only test about once a month so I see no reason to move to a digital meter. What about everyone here? I see they are discussing this at RC so I thought I would get some local opinions.

Cheers,
Patrick

[canadawest]

I've been using a "Deep Six" hydrometer for over a year and it works fine for me. Based on most opinions it is fairly accurate and is very easy to use.

They are only $12 @ J&L if I remember correctly.

[Delphinus]

Well .... I have used the plastic box swing arm types and the one thing they are good for is that they are automatically temperature corrected.

That said. Have you ever taken any two of these and gotten a consistent reading on the same sample of water? You'd be VERY surprised the range of error on those plastic swing arm types.

I personally like the glass plumb bomb type, but you have to take temperature into account to determine your salinity from SG. But with THAT said .... I tend to go through many of these per year because they are fragile and I always break them sooner or later.

The real cream of the crop is the refractometer types. These kind of look like a flashlight. It's actually more like a rudimentary microscope. You take a drop of water, place it on the glass plate, and look through the other end (pointed at a light source). The water bends the light based on the SG, and you read the value of a scale on the eyepiece. Nice, but expensive compared to the other options. And I think you still need to temperature correct.

I've never seen a digital hydrometer. I can't imagine those would be anything inexpensive....

[ 29 April 2002, 13:35: Message edited by: delphinus ]

[BCReefer]

I read about the hydrometer and I heard they are really difficult to calibrate plus they cost $65.00 US$. anyone here ever use one?

[stephane]

I use the plastic box from seatest for about six years and it never fail

I check it twice a year whit a glass one but it always good reading

BUT IMO you need to take care of them alway rinse them and put it upside down on a towel

once a year put vinegar one and let it soak one night to make shure that no mineral deposit will
stick on the arm and foul the reading

[canadawest]

Save your money and buy a swing arm type, just ask Troy. He bought a refractometer (cost around $100CDN if I recall) and out of curiosity tested both his swing-arm type hydrometers for accuracy. Both were almost dead-on when compared to a refractometer tested sample!

Rather than repeat myself, check out this discussion I participated in a couple weeks ago:

Refractometer discussion (http://www.aquariumpros.ca/forums/showthread.php?s=&threadid=540)

[ruck'n'reefer]

I'm with Andrew!! Get the Deep six.

[Delphinus]

I would still confirm any hydrometer reading against a known good hydrometer.

My first Deep Six read 0.008-0.009 low right out of the box. I had bought it right when I was getting into the hobby and I foolishly trusted it. I thought my water was 1.021 but it was 1.012. At that SG I had livestock losses after no time at all. Wasn't until I had a water sample tested by someone else did I realize what was up.

The one I have now reads 0.003 low, but at least it reads CONSISTENTLY low 0.003, so anytime I take a reading I add 0.003 and I get the "true" SG.

I'm not saying don't use these. It's your risk if you don't question a reading though. The ones I have, don't go down to 1.000 so it's not even possible to at least verify a sample of freshwater and see if you can get a value of 1.000. This is why I like the glass types better since they DO go down that far. Maybe Deep Six's design has changed in the last few years -- mine are several years old.

[ 29 April 2002, 17:16: Message edited by: delphinus ]

[SuperFudge]

Hiya Patrick,

A few samples in 4 swing arm type hydrometers that i and a friend had showed ranges .0022 upto .0026, :eek: I believe the most accurate and reliable among these was M3`s arometer,although effectivly it is still a swing arm type.(and still not very cheap at about $60)
It just uses a looser fit swing arm,with a ball bearing for a counterweight,I guess avoiding the arm joint that gets pitted with junk and fouling your reading on the other versions.

I would think that it is not too much of a concern to have any specific reading within reason,just that you have a reference point established.For that matter you could just purchase another $20 version,and always have something to compare to.

Marc.

[Troy F]

I use a refractometer and find it really easy to use but the key feature is the peace of mind knowing that your reading is accurate. Having said that; my hydrometer (cheap plastic swing arm type) was out by a very small margin.

[Dale D]

Troy.

Where did you get your refractometer from.

I'm trying to get Mike to get one.

He said sure, but, hasn't got one yet. I thought if I got all the info for him it might speed him up a bit. smile.gif

Thanks. Dale

[ 29 April 2002, 20:59: Message edited by: Dale D ]

[canadawest]

Hey Dale, I think Aquariumpros.ca has some, you could check there. Although the pricing seems a bit higher than some other MO places I've seen, you might be able to swing a business to business deal there with AJ?

[Troy F]

Dale, I got mine from Northcoast Marine down in the States via mail order. I received really good service, it was here within a week after placing the order.

www.northcoastmarines.com (http://www.northcoastmarines.com)

[Silverfish]

I am going to get myself a refractometer, just waiting to find one easily enough to make an impulse buy!

Like the ad for the refractometer on Northcoast Marines says, you invest a lot of money in your reef tanks, it would be nice to know for sure where you SG is at. ;)

[Troy F]

Patrick, I'll calibrate your hydrometer if you'd like. J&L use the cheap ones too.

[canadawest]

Patrick, good idea to start with the cheap plastic type and go big only if you feel you need to.

In regards to the TDS meter, they are used to check water purity (Total Dissolved Solids) and do not measure salinty/specific gravity. I have a digital TDS meter that I got from Reefpure when I bought my RO/DI unit. Dave threw mine in with the deal, but they only cost approx $30US.

Troy, next time you're out Surrey way, or I'm out your way I'd love to check my Deep Six hydrometer against your refractometer for accuracy. I'd even give you $5 for your time and the fact you spent the $$ on the nice equipment.

[Troy F]

Andrew, I live about ten blocks east and ten blocks north of you. If I was charging, my time would be worth more than five bucks though ;) . Let me know when you are free.

[canadawest]

I'm free most evenings and weekends. I'll send you a private email and we'll connect.

Are you planning on doing the "Island Reef Tour" meeting next month? If so perhaps we can wait until then?

[BCReefer]

Thanks everyone. I think I will start off with the cheap one and take some water to J&L and get them to test. If the reading are close then I will keep the cheapo. If I see larger variances then I will look at a more expensive system.

When I worked in the hydroponics business, we had TDS digital testers. They are about $150.00 ?? CDN$ and are on at all times. anyone else using one?

Thanks
Patrick