gopens Posted October 4, 2006 Share Posted October 4, 2006 well i have been using a hydrometor for a few weeks now for both my main tank and the q-tank. i have been doing a hyp in the q-tank with some percs. over the last 5 days i have slowely lowered my salinity from .026 to .020 in my q-tank. being that i am shooting for a final salinity of .009, i decided to get a refractometor being i have heard that hydrometors can be a bit off. well today i got the refractometor. i checked my q-tank with the refractometor and it said it was .025. but my hydrometor says .020. is it possible for them to be that much off. i understood that a hydrometor was not super accurate, but pretty close. is it possible that one may be broke or is it common to have that big of a difference in the two. also my refractometor came with a little screw driver. do i need to mess with the settings in some way or is it exactly what it says, .025. Quote Link to comment Share on other sites More sharing options...
CCR Posted October 4, 2006 Share Posted October 4, 2006 Yes it can be off. The refracto, needs to be calibrated. I don't beleave the hydo, is that far off, if anything, take a reading with both, then take them BOTH to your reliable SW store, and check BOTH in there water, and against there readings in shop. They can help you calibrate it. Keep it dried, keep SW off the little screw on the top, or it will rust, get one that is tempiture compensating, and don't keep it on the tank, It will give a false reading, as the temp will be raised on the unit from the heat on hood Quote Link to comment Share on other sites More sharing options...
gopens Posted October 4, 2006 Author Share Posted October 4, 2006 i just read online that you can simply use distilled water and set it to zero. has anybody done that? Quote Link to comment Share on other sites More sharing options...
nu2reef-n Posted October 4, 2006 Share Posted October 4, 2006 I use RO water to zero mine. I checked it against the local pet stores refractometer to make sure mine was right on. Quote Link to comment Share on other sites More sharing options...
Guest Mbeef61 Posted October 4, 2006 Share Posted October 4, 2006 i agree with nu2reef-n....ro and a check with another is always reassuring Quote Link to comment Share on other sites More sharing options...
reefhut Posted October 4, 2006 Share Posted October 4, 2006 Alway's calibrate a refractometer with distilled water to set it to zero. I hear you shouldn't use RO water. When you test salanity make sure the water temp is at tank temp.( some people test salinity the same time there testing water peram's, meanwhile water get's cooled down and that will effect your reading) Quote Link to comment Share on other sites More sharing options...
fly guy Posted October 4, 2006 Share Posted October 4, 2006 Alway's calibrate a refractometer with distilled water to set it to zero. I hear you shouldn't use RO water. ) Anybody know why??? I have always used my ro/di water to calibrate. ???? Quote Link to comment Share on other sites More sharing options...
CCR Posted October 4, 2006 Share Posted October 4, 2006 Anybody know why??? I have always used my ro/di water to calibrate. ???? I have done the same as you ro/di, then I took it down to lsf, and it was 2 points off. I have read in the instructions, in the past to use distiled water. Don't have any idea why there would be a difference. Quote Link to comment Share on other sites More sharing options...
fly guy Posted October 4, 2006 Share Posted October 4, 2006 I have done the same as you ro/di' date=' then I took it down to lsf, and it was 2 points off. I have read in the instructions, in the past to use distiled water. Don't have any idea why there would be a difference.[/quote'] which direction was it off?? Quote Link to comment Share on other sites More sharing options...
reefboy Posted October 4, 2006 Share Posted October 4, 2006 distilled water as ben boiled so most impurties are gone so im gessing more of a fail safe if your buying the water to calibrate the distilled is a safer bet then some peoples ro water Quote Link to comment Share on other sites More sharing options...
gopens Posted October 4, 2006 Author Share Posted October 4, 2006 well i used ro water and it was still way off from the hydrometor. i am going to try distilled later Quote Link to comment Share on other sites More sharing options...
CCR Posted October 4, 2006 Share Posted October 4, 2006 well i used ro water and it was still way off from the hydrometor. i am going to try distilled later RO would be off. make sure the distilled is at room temp. Get to work!!! winter is comming. Ya better have a good storage of nut's!!!! cause the tank is added expence on the budjet!!!!(laugh) Quote Link to comment Share on other sites More sharing options...
impur Posted October 4, 2006 Share Posted October 4, 2006 I use RO too. Odd. My directions say to use RO or distilled. And if your refractometer is ATC (automatic temp compensation) you should be fine. Quote Link to comment Share on other sites More sharing options...
JManrow Posted October 5, 2006 Share Posted October 5, 2006 Distilled water, in addition to being boiled, has been converted into steam, then condensed back into very pure water with salts and impurities left behind. RO or DI water may be very close to Distilled Waterwhen the membrane or deionizing beads are new, but they gradually lose their effectiveness during use. RO/DI water becomes "less pure" over time, and membrane and bead cartridges must be eventually replaced to again have "pure" product water. Purity can affect the calibration. If someone wants very pure water, double and even triple distilled water is available. Quote Link to comment Share on other sites More sharing options...
drock59 Posted October 5, 2006 Share Posted October 5, 2006 I am confused. Is it not better to use RO/DI water then distilled in your tank? Why not use RO/DI for the refracto? This doesnt make any sense to me. Could someone please try again? Quote Link to comment Share on other sites More sharing options...
fly guy Posted October 5, 2006 Share Posted October 5, 2006 Distilled water, in addition to being boiled, has been converted into steam, then condensed back into very pure water with salts and impurities left behind. RO or DI water may be very close to Distilled Waterwhen the membrane or deionizing beads are new, but they gradually lose their effectiveness during use. RO/DI water becomes "less pure" over time, and membrane and bead cartridges must be eventually replaced to again have "pure" product water. Purity can affect the calibration. If someone wants very pure water, double and even triple distilled water is available. So if my quality TDS meter says ZERO, wouldnt that be good enough to calibrate off of??? im kinda confused too drock59 Quote Link to comment Share on other sites More sharing options...
drock59 Posted October 5, 2006 Share Posted October 5, 2006 Ya, i dont get it. I could boil some water with a tds of 443 and collect the steam and call it distilled. How is that better than RO/DI? Quote Link to comment Share on other sites More sharing options...
blown65 Posted October 5, 2006 Share Posted October 5, 2006 RO usually wont do 0 TDS unless your water is made up with easily rejected minerals etc etc. Most the time you will end up with 3-10 TDS and depending on whats making that up could effect the Refract meter. The post DI cartridge should remove the rest, but dont count on it. Some of the hobby ones seem to be of low quality IME. Even some of the cheap commercial ones I have are borderline (just not regenerated correctly I believe in the media.) Distilled would probably be the best choice if you wanna be 100% or as close to 100% accurate. RO/DI is fine as long as the water is actually 0TDS. Thats why I dont use carbon on my postfilters from an RO. They tend to leach phosphates back into the water and raise the TDS. Then your DI filter just has that much more to take out and doesnt last as long. I have a chart that shows all the different things at thier givin rejection rates if anyone is interested. Just gotta get a copy onto the PC. Quote Link to comment Share on other sites More sharing options...
fly guy Posted October 5, 2006 Share Posted October 5, 2006 RO usually wont do 0 TDS unless your water is made up with easily rejected minerals etc etc. Most the time you will end up with 3-10 TDS and depending on whats making that up could effect the Refract meter. The post DI cartridge should remove the rest, but dont count on it. Some of the hobby ones seem to be of low quality IME. Even some of the cheap commercial ones I have are borderline (just not regenerated correctly I believe in the media.) Distilled would probably be the best choice if you wanna be 100% or as close to 100% accurate. RO/DI is fine as long as the water is actually 0TDS. Thats why I dont use carbon on my postfilters from an RO. They tend to leach phosphates back into the water and raise the TDS. Then your DI filter just has that much more to take out and doesnt last as long. I have a chart that shows all the different things at thier givin rejection rates if anyone is interested. Just gotta get a copy onto the PC. Everything you mention here is not only true, but a solid case for buying quality RO/DI untis and replacement filters along with testing for tds regularly Leaching phosphates back in is only due to neglectful maintenance or an low quality unit/filters in the first place........of course us getting too much into this conversation is kind of getting this thread off topic : ) Quote Link to comment Share on other sites More sharing options...
drock59 Posted October 5, 2006 Share Posted October 5, 2006 So you are telling me that Distilled water is more pure than RO/DI water? I just want to clarify. Quote Link to comment Share on other sites More sharing options...
blown65 Posted October 5, 2006 Share Posted October 5, 2006 So you are telling me that Distilled water is more pure than RO/DI water? I just want to clarify. It can be depending on the quality of your RO/DI water being created. More importantly the performance of the DI filter itself. The DI filter "should" remove 100% of the contaminents left at the correct flow rate of the unit. Find yourself a water treatment company and have them test your TDS from your RO/DI. Id actually do it after the RO and then after the DI so you can see how each is performing. Otherwise buying a decent quality TDS meter is fairly cheap. Quote Link to comment Share on other sites More sharing options...
blown65 Posted October 5, 2006 Share Posted October 5, 2006 Everything you mention here is not only true' date=' but a solid case for buying quality RO/DI untis and replacement filters along with testing for tds regularly Leaching phosphates back in is only due to neglectful maintenance or an low quality unit/filters in the first place........of course us getting too much into this conversation is kind of getting this thread off topic : )[/quote'] Actually you can take a brand new charcoal filter (I'm talking about the water treatment style, not the aquaria media) from Lowes or where ever your getting your RO filters from. It will be doing two things, leaching phosphates into the water and raising the TDS (even if its 1 TDS, its 1 more TDS for your DI to remove). There really arent many high quality charcoal cartridge filters out there that wont leach stuff back in. Bulk media yes, but most the ones Ive tested almost always raise TDS, and some leach a crap load of phosphates. You can however buy empty canisters and not use those cartridge style charcoal filters, then use that as your post filter on an RO with aquaria grade charcoal. I dont think there is any good to be gained doing so though, but then again, I could be mistaken. Quote Link to comment Share on other sites More sharing options...
fly guy Posted October 5, 2006 Share Posted October 5, 2006 hmmmm......guess i dont know...i know i could probably save a buck or two if i paid more attention to each part of the process.....when my tds hits 1 on the output i simply replace all 3 filters. Ive never replaced my membrane. Ive never tested anything but the final product Quote Link to comment Share on other sites More sharing options...
blown65 Posted October 5, 2006 Share Posted October 5, 2006 hmmmm......guess i dont know...i know i could probably save a buck or two if i paid more attention to each part of the process.....when my tds hits 1 on the output i simply replace all 3 filters. Ive never replaced my membrane. Ive never tested anything but the final product Thats fine, I was just saying what the post filter does sometimes. Just depends I guess is what I was trying to get at. If your not having issues and your tds is in check, dont worry bout it. I know my 0 tds RO/DI and the Distilled water made my refract meter show the same number. Quote Link to comment Share on other sites More sharing options...
fly guy Posted October 5, 2006 Share Posted October 5, 2006 If your not having issues and your tds is in check, dont worry bout it. I know my 0 tds RO/DI and the Distilled water made my refract meter show the same number. THATS what i wanted to hear right there. : ) ive kind of been wondering what my salinity REALLY is since the beginning of this thread......... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.