I just treated the tank for flatworms, so I did a water change, but my tank reading was unexpectedly low. I want to recalibrate my refractometer to make sure that it’s in spec. Anybody got any spare salinity calibration fluid around they wouldn’t mind giving/selling to me?
If your close to dpa they normally have it,but that’s the obvious answer.
Placed an order with them, but could take 3-4 weeks. Kind of long
[quote=“bnelson, post:3, topic:8220”]
Placed an order with them, but could take 3-4 weeks. Kind of long[/quote]
Wow really? Amazon can have it to you in a day or 2
I know and it will probably be cheaper too, but I’m trying to support the LFS.
[quote=“bnelson, post:5, topic:8220”]
I know and it will probably be cheaper too, but I’m trying to support the LFS.[/quote],
I hear ya, but when you need somthing today and can have it tomorrow its hard to do. If your gonna be near dover bring your refractor over and I will check it for you
I have some of the distilled calibration solution, not the 35 ppt stuff. If you want, you’re more than welcome to stop by. I’m in Middletown though, a little bit of a hike, but not that bad.
If I do make my way south in the next 3-4 weeks then I’ll probably hit you guys up, thanks.
well, for DIY you already have RO water or can use distilled water for the 1.000 reading, and randy Holmes Farley, From RC published this method for making DIY 35 ppt cal solution on ReefKeeping.
http://www.reefkeeping.com/issues/2004-06/rhf/
He says you can use cooking measuring spoons for the salt. Getting a good close volume measure of water needs a calibrated jar, or fiddle with the 2 liter bottles as he explains. Math implies that the larger batch you make, the more accurate it will be because your measuring error at the margin becomes smaller by comparison to the volume.
I have a tiny digital scale, from harbor freight, about the size of a pack of cards, accurate to 1/10 gram if you want to weigh the salt and RO water and not worry about volume. Much More accurate. I would bake the salt first in the oven to dry it out. its hydrophylic.
Or we could compare your refractometer readings with mine. should be like new, havent used it in years. just my old swing arm meter to get close enough.
The problem with using Rodi to cal is that it’s very far from where ur measuring. Ideally you want to cal as close to where ur measuring as possible for the best results.
Great idea Ken! Especially about baking the salt! I think I’ll give that a try after I replace my Rodi filters. I have a tds meter so I can verify 0 tds.
Well Bryant, you can always use a jug of distilled water from the store for the 1.000 cal. If you want to make a small batch, like 500 ml of 35ppt saline solution, give me a shout, I’ll drop by with the little scale. Just have a clean and dry 1 liter soda bottle with cap ready, and your baked, dehydrated table salt, and it wont take no time at all.
All’s we do is place the empty plastic bottle on the scale, then turn the scale on . It then takes a few seconds to calibrate the weight of the bottle as the zero setting. then add the calculated weight of RO water, or distilled water if you like, and then add the calculated weight of salt, and should weight 500 grams total. then cap and shake, not stir, until all dissolved. And Voila~~ 35 ppt cal solution.
I checked the scale. its 1/10th gram accuracy is equal to roughly 3 drops of water. so it should be very accurate concentration. Using actual salt weight will be more accurate than dry measures of volume. crystal size and air space between particles can make a big difference.
did you ever get squared away?
Not yet. I just did my bi-annual water change so I’m not in a huge rush ATM.
Did you get your Calibration fluid? or would you like to try the DIY?
I just bought a brand-new bottle of it welcome to calibrateyour peace with it if you like
Lee, that would be great! Are you going to the BBQ? Your down by Dover correct?
[quote=“bnelson, post:16, topic:8220”]
Lee, that would be great! Are you going to the BBQ? Your down by Dover correct?[/quote]Im in townsend and work in Wilmington but not sure yet on BBQ my sister is getting married the 8th so its still up in the air im sure we could make it work so you get strait
I’ve got two types that I purchased six months ago so I know they’re good. One is the sea water, the other the calibrated fluid. You’re welcome to swing by bryant.