Old wives tales- or are they?!

[rbursek]

From I get out of it is the RODI changes the slope for useing it with salt water, and when I was in a tread with Randy, like I said, you told me to look at the difference that RODI read after calibrateing with 35s. Boomer chimed in on RS and said the same. I can't say anymore.

[jmaneyapanda]

Originally posted by rbursek
From I get out of it is the RODI changes the slope for useing it with salt water, and when I was in a tread with Randy, like I said, you told me to look at the difference that RODI read after calibrateing with 35s. Boomer chimed in on RS and said the same. I can't say anymore.

Hmmm... I dont get that at all. The slope accuracy is a quality of the refractometer for a certain media, not the media itself. Different refarctometers are created for different applications, and have a slope "generalized" to the intended purpose.

At any rate, I get the feeling we are both amateurs when it comes to this, so I will just research it more myself, rather than just bickering (which I often do). Thanks for the insight and the link.

[rbursek]

Your welcome, and maybe Boomer will chime in but this forum is not one of his hang outs, more the Chem forum. A good tread thou, I am surprized they have not been more post on your subject.

[styndall]

Apropos the mantis:

There was a thread here a few months ago wherein a guy got thumped by a hitch-hiking mantis and loss a pretty chunk of flesh from a hand. He posted photos of both the mantis and the wound.

It may not be losing a thumb, but I still wouldn't want to get hit by a mantis.

[SeanT]

Years ago many thought that certain light spectrums, even sunlight was the "CAUSE" of hair algae.

IT'S THEM DARN PHOSPHATES!!!

[nalbar]

I thought you were supposed to use DISTILLED water to calibrate a refractometer. That is what the directions say on mine.

nalbar

[rbursek]

Not if you want to use it for salt water. Refractormeters are used for many different liquids to check for SG, beer, syrup, ect. Go to the chem forum and pull up the tread I mentioned above and read Randys article.

[nalbar]

LOL!

Whatever.


nalbar

[useskaforevil]

refractometers that are used for sugar content for syrup have a different range than our refractometers. and if you cannot calibrate a refractometer with distilled water (or any other substance that should be on its scale) than it is inaccurate at any reading other than exactly what you calibrated it at.

[jtma508]

FWIW I initially calibrated my refractometer with RO/DI water 'cause I didn't have any saline standard on-hand. When I got some and recalibrated the unit it was dead-on. Go figure.

[Michael]

http://reefkeeping.com/issues/2006-12/rhf/index.php

[spleify]

It was my understanding also that it will read low if calibrated with RODIwater

Spleify

[widmer]

Wow, time to rename this thread: "Lengthy refractometer argument (when a $7 hydrometer works perfectly fine), with a touch of mantis shrimp."

lol

[RRaider]

Here is an interesting article on the damage a mantis shrimp can do.

http://www.usatoday.com/tech/columni...9-shrimp_x.htm

[greenbean36191]

I've personally seen a few people get their "thumbs split" by mantis shrimp pulled up in trawls, though I don't have pics. I would venture that most experienced commercial shrimpers/ fishersmen have had a few run-ins with mantis shrimps. I'm not sure where you've heard a myth about severing appendages though. That's a new one to me.

[seapug]

I've seen pics posted here of the damage mantis shrimps can cause. The finger removal stories might be a bit exagerrated, but the picture I saw didn't look like fun and it was from a small mantis. In theory, I would imagine one that's a foot long could cuase some pretty serious trauma.

[FishBait]

My first hand experience is watching a mantis bust up sizeable pieces of live rock while doing some home "renovations." My common sense tells me if it can do that to rock, my skin likely isn't going to slow it down much. I can believe a large enough mantis may be able to break finger bones. Not sure about taking the digit off entirely, but I don't need to go that far to see how unpleasant a thwack could be

[kstallbe]

Okay, so if you have a quality refractometer (calibarted using RODI), but it was intended to measure only NaCl solutions, rather than seawater the diffc. would be 0.0003. I think most of us can live with that, and I'm guessing this would be the case for most of us.

However, if the refractometer isnt intended for saltwater use at all or is just a piece o junk, then it is much more significant to calibrate it using a standardized solution.

[superfirefly]

Here are the thumb splitters. Friend of mine ordered this in China.

[Bruno3047]

I've still not bought into the idea that you can reduce your nitrate load by simply removing the bio-balls from your wet/dry filter. There’s no science to back this up.

I've searched all over the web for any substantive evidence that this is true, but have been unable to find any. I even went so far as to post a thread on the Reef Chemistry forum asking for some kind of empirical evidence to back this up, but got nothing, other than anecdotal commentary, which means nothing since I have experience to the contrary.

Now, if you’re having a severe algae bloom and you decide to remove your bio-balls AND turn the bio-ball space into a refugium filled with sediment and algae, and maybe reduce feedings etc., then I believe that will help reduce nitrates.

But removing the bio-balls only?

No way. A fairy tale.

[Icefire]

rbursek, jmaneyapanda is right, a good quality refractometer not made in china, with a proper calibrated slope of the scale should read 1.000 with RODI and 1.0264 (35ppt) with 53mS solution.
Most refractometer we use are made in china, by some "slave" and they aren't that good. so we take a reference point (53mS) and now we test our water and we want it to be 53mS, so the mesure will be good.

Bruno I think like you on bioballs, they only extend place where bacteria can colonize. remove them and bacteria will colonize the rock/sand more. Having them in Air/Water might give them more O2 for reducing to NO3 but if you get NO3 with bioballs, you have excess wastes.

[Bruno3047]

Icefire - It's true that if you remove the bio-balls, the bacteria will colonize exclusively on the sand and rocks, but the sand and rocks will not provide the high oxygen content envoirnment that a wet/dry setup does. And if you're ever in need of a hastly increase in your bacteria (e.g. something unseen dies in your tank), the rocks and sand will not help you.

The bio ball wet/dry setup will.

[Doahh]

My Refractormeter (Quality made in the USA) says to calibrate with Ro/Di for Saltwater use

[greenbean36191]

If you're calibrating outside the range you intend to use and assume that the slope is correct then you've defeated the purpose of calibrating in the first place. The whole point of calibration is that you can't assume accuracy in an instrument unless you set it against known values.

[jmaneyapanda]

Originally posted by greenbean36191
If you're calibrating outside the range you intend to use and assume that the slope is correct then you've defeated the purpose of calibrating in the first place. The whole point of calibration is that you can't assume accuracy in an instrument unless you set it against known values.

That is not the point of calibration at all. I understand your point, and as I stated previously, calibrating with salinity fluid is superior to calibrating with RODI, but I truly feel it is an innaccurate statement to say that all refracts. calibratetd with RODI are wrong.