Deep Six Hydrometer

Matt Rogers · 05-20-2003, 07:18 AM

Yesterday I bought one of these because the LFS was out of the sea test hydrometer I used to own. (Sorry, I am not one of those guys who thinks it's neccessary to have a refractometer.

)

The 'Deep Six' was a couple bucks more, but it is pretty nice! The water line is self-leveling so you always get an accurate read. It has a large range and also gives you ppt. They say it also is temperature corrected for aquariums.

The way it's designed, you can dip it 6 inches below the surface of the water and fill it without getting your hand in the tank. Pretty cool.

The only thing that made me pause is that they want you to 'season' the needle for 24 hours with water prior to taking the first reading. They don't say whether you season it with salt or fresh water. I went with salt, but I really have no idea if I am right. Anybody?

Anyway, I paid $12.99 + tax and I think it was worth the extra couple bucks over the usual.

[smiley=2thumbsup.gif]

Craig Manoukian · 05-20-2003, 07:36 AM

[glow=red, 2, 300]I've heard great thing about the Deep 6 Hydrometer![/glow]

Matt Rogers · 05-20-2003, 07:53 AM

Cool.

You know what though Craig? I noticed the ppt and specific gravity are measured off the same needle. Isn't it possible to have different readings for both? I don't think it's possible with this thing. Unless they both are changing with the temperature.

I'm confused. [smiley=stars.gif]

Craig Manoukian · 05-20-2003, 08:08 AM

I've never used them, but when I asked about hydrometers on RAG the overwhelming response was for the Deep 6. Will have to get one and see.

Matt Rogers · 05-20-2003, 08:17 AM

That's one way to find out!
If you do, let me know what kind of water you decide on for the 'seasoning.'

[smiley=thumbs_up1.gif]

Wrassman · 05-20-2003, 09:50 AM

[glow=Blue, 2, 80%]Hey Matt,

I don't know anything about the 'seasoning.' But, I do know that the "specific gravity" of natural seawater is 35, and that hydrometers are based on that assumption. The makers of hydrometers build the SG/Salinity ratios around the 'numbers' for natural seawater.

So, unless your aquarium is grossly out of whack, salinity and specific gravity should come out more or less equal every time.

HTH[/glow]

Matt Rogers · 05-20-2003, 11:28 AM

Thanks Wrassman. I will take a closer look when I get home. FWIW, it is telling me my NSW out of the collection bottle is 1.024.

Craig Manoukian · 05-20-2003, 03:30 PM

That doesn't sound out of bounds. *Isn't most SW around 1.025 - 1.026? *I know the mean Salinity for the Indo-Pacific is 36ppt and that an SG of 1.025 at 80 degrees is 36ppt. *An SG of 1.025 at 78 degrees yieds 36 ppt.

Matt Rogers · 05-20-2003, 04:35 PM

That's interesting Craig and pretty much shows the ppt on this thing may be gimicky because no matter the temperature, ppt and specific gravity cannot change independently on this thing.

Thanks guys!

Wrassman · 05-22-2003, 06:21 AM

Hey Matt,

I was reading my Drs. Foster & Smith catalog and came across your Deep Six Hydrometer. It says in here that it "gives temperature-corrected readings in warm water aquariums." Whatever that means, I hope it helps...