Whys
New member
Hydrometers are crap, no doubt. I recently switched to a refractometer. I know a few of you just gasped in disbelief, but it's true, a refractometer can be a splendid thing, however... there's always a caveat. 
Hydrometers have their place, just as refractometers do. Are they less accurate? Sure. Do they suffer from user error? Often. Are they useless junk? No, they aren't, it just depends on what you want to do. Allow me to explain.
I've had my reef up and running for nearly 6 months. In this time I have added: snails, brittle-star, hermits, sexy-shrimp, emerald crab, red-striped goby, court-jester goby, watermelon mushroom, and a frogspawn. All of these are fairly hearty and good for beginners. Thus I've had no trouble relying on my reliably less accurate hydrometer. I've thoroughly rinsed my hydrometer with fresh water after every use. I've carefully examined the arm for tiny bubbles when taking a reading. And perhaps most importantly, I've only been shooting for the center of the safe range. Why is that last one so important? Because as my refractometer now tells me, my hydrometer is off by 4 points! To be fair, that number doesn't change. It's always off by 4 points and always in the same direction. This is not an abnormal variance for a hydrometer and as long as I keep it clean and always shoot for the middle, everything remains safe. But now comes the next part.
I recently added my first SPS with hopes of adding more, so of course, I'm concerned about c0ral growth. What I have come to understand is that specific gravity can have a significant impact on other elements of water chemistry. For this reason, many hobbyists like to keep their specific gravity much closer to the upper limit at around 1.025 to 1.026. It is at this point that accuracy really matters. If I were to rely on my hydrometer to keep my SG at 1.025, it would actually be at 1.029. Yikes! :eek1:
So what's the moral of the story? My refractometer is wonderful and I'll never use my hydrometer again. None-the-less, it has served me well in these first 6 months while my biggest concerns have been about establishing my cycle, controlling algae growth, and learning to care for a beginner's reef. I think of it like my secret captain decoder ring that came with the box. Sure, it's a plastic piece of crap, but it's still great for the kids stuff. I might keep it on my mantle.
By the way, the secret message was... get a refractometer!
Peace out.
Hydrometers have their place, just as refractometers do. Are they less accurate? Sure. Do they suffer from user error? Often. Are they useless junk? No, they aren't, it just depends on what you want to do. Allow me to explain.
I've had my reef up and running for nearly 6 months. In this time I have added: snails, brittle-star, hermits, sexy-shrimp, emerald crab, red-striped goby, court-jester goby, watermelon mushroom, and a frogspawn. All of these are fairly hearty and good for beginners. Thus I've had no trouble relying on my reliably less accurate hydrometer. I've thoroughly rinsed my hydrometer with fresh water after every use. I've carefully examined the arm for tiny bubbles when taking a reading. And perhaps most importantly, I've only been shooting for the center of the safe range. Why is that last one so important? Because as my refractometer now tells me, my hydrometer is off by 4 points! To be fair, that number doesn't change. It's always off by 4 points and always in the same direction. This is not an abnormal variance for a hydrometer and as long as I keep it clean and always shoot for the middle, everything remains safe. But now comes the next part.
I recently added my first SPS with hopes of adding more, so of course, I'm concerned about c0ral growth. What I have come to understand is that specific gravity can have a significant impact on other elements of water chemistry. For this reason, many hobbyists like to keep their specific gravity much closer to the upper limit at around 1.025 to 1.026. It is at this point that accuracy really matters. If I were to rely on my hydrometer to keep my SG at 1.025, it would actually be at 1.029. Yikes! :eek1:
So what's the moral of the story? My refractometer is wonderful and I'll never use my hydrometer again. None-the-less, it has served me well in these first 6 months while my biggest concerns have been about establishing my cycle, controlling algae growth, and learning to care for a beginner's reef. I think of it like my secret captain decoder ring that came with the box. Sure, it's a plastic piece of crap, but it's still great for the kids stuff. I might keep it on my mantle.
By the way, the secret message was... get a refractometer!
Peace out.
