hovmoller Posted June 27, 2014 Report Share Posted June 27, 2014 Thought it would be interesting to see what TDS (Total Dissolved Solids) people get around the country out of the tap. I'll start: Titirangi, Auckland (water from Waitakere dams) Tap: 77ppm Rain (from downpipe): 9ppm Quote Link to comment Share on other sites More sharing options...
Ira Posted June 27, 2014 Report Share Posted June 27, 2014 Thought it would be interesting to see what TDS (Total Dissolved Solids) people get around the country out of the tap. I'll start: Titirangi, Auckland (water from Waitakere dams) Tap: 77ppm Rain (from downpipe): 9ppm Mail me your TDS meter and I'll tell you. Quote Link to comment Share on other sites More sharing options...
Trelize Posted June 27, 2014 Report Share Posted June 27, 2014 79ppm in mt Wellington Quote Link to comment Share on other sites More sharing options...
Adrienne Posted June 27, 2014 Report Share Posted June 27, 2014 86ppm Epsom, Auckland Quote Link to comment Share on other sites More sharing options...
David R Posted June 27, 2014 Report Share Posted June 27, 2014 6-9ppm out of the tap (rain water), tank fluctuates between about 50-60ppm, I think. Haven't checked it for a while now... Quote Link to comment Share on other sites More sharing options...
kinnadian Posted June 28, 2014 Report Share Posted June 28, 2014 It was 240ish in Christchurch a couple years ago, around 1 year after the Feb earthquake (drinking water was still shitty). 56 in New Plymouth. We are lucky in NZ, in places like America where water is recycled thousands of times you get hundreds of ppm as normal. Quote Link to comment Share on other sites More sharing options...
KrazyGeoff Posted July 3, 2014 Report Share Posted July 3, 2014 60 ish, tararua tap water Quote Link to comment Share on other sites More sharing options...
Rouseabout Posted July 7, 2014 Report Share Posted July 7, 2014 Hi Im wanting to get into using TDS as the main indicator test of my tanks water quality - recommendations on what meter to purchase and where from please? Thanks chris Quote Link to comment Share on other sites More sharing options...
kinnadian Posted July 7, 2014 Report Share Posted July 7, 2014 Depending on your budget, HM ones are considered quite good for the money, factory calibrated. http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=hm+tds Hanna are good as well but much more expensive. Quote Link to comment Share on other sites More sharing options...
Rouseabout Posted July 7, 2014 Report Share Posted July 7, 2014 Cheers Kinnadian There are heaps on there - for hand-held use (multiple tanks) which one would you go for if price no issue? also, assume I would need at least one calibration solution also? Quote Link to comment Share on other sites More sharing options...
Adrienne Posted July 8, 2014 Report Share Posted July 8, 2014 Mines an HM - as an option on it to measure temperature as well and a hold button so you can pull it out and it won't change in the process. I don't know about the calibration but I think I need to find out. I got mine off Valray on ™. $35 Quote Link to comment Share on other sites More sharing options...
David R Posted July 8, 2014 Report Share Posted July 8, 2014 Sounds like the same as mine Adrienne, let me know what you find about the calibration, I guess it is probably time to do mine. It would be interesting to do a side-by-side comparison with a few different meters some time. Quote Link to comment Share on other sites More sharing options...
kinnadian Posted July 8, 2014 Report Share Posted July 8, 2014 Cheers Kinnadian There are heaps on there - for hand-held use (multiple tanks) which one would you go for if price no issue? also, assume I would need at least one calibration solution also? Hanna are basically laboratory-grade units, HM are consumer grade. I think both will probably have similar accuracy, Hanna just has more features and are built better. Hanna will probably be better calibrated for non-room temperature solutions. Most of the decent tds meters from calibrated from factory, but getting some calibration solution will be good at the same time so you can use it later on down the track. I think you'd be happy with HM TDS-3 or 4 or TDS-EZ. However if you are reaching into water tanks a lot you might want to get one of the Hanna instruments with a long cable, which often have pH as well which is a bonus. Inline meters are generally not as accurate as handheld ones. Quote Link to comment Share on other sites More sharing options...
KrazyGeoff Posted July 8, 2014 Report Share Posted July 8, 2014 I have this one: http://www.amazon.com/Hanna-Instruments ... KHNTMFANEK Calibration fluids etc can be purchased from blu lab which is a nz company. http://www.bluelabassist.com/shop/By+Ca ... %3D(direct)%7Cutmcsr%3D(direct)%7Cutmcmd%3D(none)&__utmv=-&__utmk=262338957 It takes about 40 seconds to do a complete suite of readings per tank. (About 3 seconds for TDS) Really easy to calibrate, especially the new generation model. ( the one in the link ) Temp, pH, TDS, conductivity. It also adjusts for temperature variance from 25 degrees. I have used other pH meters and found that this one reacts more quickly than the others. Cheers Quote Link to comment Share on other sites More sharing options...
Flosty Posted July 8, 2014 Report Share Posted July 8, 2014 Just tested mine and it was 138 ppm out of the tap, out of my RO unit it is 9 ppm My discus still breed fine in tap water Quote Link to comment Share on other sites More sharing options...
David R Posted July 8, 2014 Report Share Posted July 8, 2014 Might want to check the calibration of your meter, or the cartridges in your RO, as RO water should be 0ppm. Quote Link to comment Share on other sites More sharing options...
kinnadian Posted July 8, 2014 Report Share Posted July 8, 2014 Just tested mine and it was 138 ppm out of the tap, out of my RO unit it is 9 ppm My discus still breed fine in tap water Alternatively it might be time to change your RO membrane or DI resin. Do you know how long ago these were done? DI resin should last 1-2 years and RO 2-3 years. Of course you can put this off but TDS will start to creep up. Quote Link to comment Share on other sites More sharing options...
Flosty Posted July 11, 2014 Report Share Posted July 11, 2014 Might want to check the calibration of your meter, or the cartridges in your RO, as RO water should be 0ppm. Thats a point, I just checked my 4 way shut off valve and that seems to be faulty. I have had this before Quote Link to comment Share on other sites More sharing options...
Adrienne Posted July 12, 2014 Report Share Posted July 12, 2014 My RO is coming out at 2. I've just purchased a replacement carbon filter. I've had the current one for 6 months, and have produced around 450 litres of RO water so that should equate to about 1800 litres waste. Quote Link to comment Share on other sites More sharing options...
Rouseabout Posted July 12, 2014 Report Share Posted July 12, 2014 Im likely to be purchasing a TDS meter within next month. So far I have seen lots of TDS readings for rain/bore/tap water - what about readings in your tanks e.g. just after water change, week after water change, longer? I guess what I'm interested in is what would be a TDS reading that would prompt a water change in different types of aquariums? Quote Link to comment Share on other sites More sharing options...
kinnadian Posted July 13, 2014 Report Share Posted July 13, 2014 TDS in an aquarium is meaningless. TDS will pick up free ions like calcium, magnesium, iodine, nitrate, phosphate, silicate, etc. Some are beneficial, others not. Everyone's TDS on their tank will be different due to their water chemistry, bioload, filtering ability, etc. You should be doing weekly water changes at a minimum, and the prompt to do a water change or not should be the result of your test kits when testing for whatever you are concerned about (typically only nitrates in freshwater, but a lot of stuff for marine). I believe you are freshwater only? In that case, TDS is not that important really, as long as it is not excessively high, since there will naturally be a lot of different ions in your bore water, some bad and some good, and a TDS meter does not analyse what is actually the dissolved solids, only that there are some. Phosphates and silicates are typically the worst for freshwater, and heavy metals (but these are unlikely). More specifically, you will be concerned about pH, which may require you to dose buffer to get your target pH. Quote Link to comment Share on other sites More sharing options...
David R Posted July 13, 2014 Report Share Posted July 13, 2014 More specifically, you will be concerned about pH, which may require you to dose buffer to get your target pH. As I understand, pH generally isn't as important as hardness and conductivity as they have an effect on the osmoregulation of the fish. Water parameters should always be looked at as part of a big picture though, and TDS/conductivity is useful as it takes into account things like salts that have an effect on osmoregulation but aren't measured when testing pH and hardness. I've read a good article on the subject but I don't have it bookmarked on this computer, will post it later. Quote Link to comment Share on other sites More sharing options...
Rouseabout Posted July 13, 2014 Report Share Posted July 13, 2014 Im doing weekly water changes etc and yes my aquariums are all fresh water. By your logic Kinnadian none of the tds readings posted here have any meaning..or value.....? I beg to differ. Considering the initial readings for tap/rain/bore water, subsequent readings in the aquarium over time must surely be measuring initial reading +increases in soluble solids load....which in a well cycled tank would be predominantly nitrates? Quote Link to comment Share on other sites More sharing options...
Mirio Posted July 13, 2014 Report Share Posted July 13, 2014 By your logic Kinnadian none of the tds readings posted here have any meaning..or value.....? They are much more relevant if you have a marine aquarium. Most people test for TDS when they're adding freshwater/RO/top-off water into a salt water aquarium (to replace the water that has evaporated) or when mixing new salt water, in which case the lowest TDS possible is desired. Testing the TDS of your aquarium be it marine or freshwater isn't really anything to go by as much as other parameters are. There likely are a few niche purposes for Freshwater aquariums, but as a whole I think it's something most people don't need to bother with. I have about 65 TDS on average, straight from the tap. Quote Link to comment Share on other sites More sharing options...
kinnadian Posted July 14, 2014 Report Share Posted July 14, 2014 Im doing weekly water changes etc and yes my aquariums are all fresh water. By your logic Kinnadian none of the tds readings posted here have any meaning..or value.....? I beg to differ. Considering the initial readings for tap/rain/bore water, subsequent readings in the aquarium over time must surely be measuring initial reading +increases in soluble solids load....which in a well cycled tank would be predominantly nitrates? Echoing what Ethanyo has said, TDS readings are predominantly for marine aquariums. They are definitely important for this application, but not really for freshwater. The reason for this is that people run RO/RODI systems for purifying their water prior to using it for a marine aquarium. The TDS of your tap water is important because it indicates how frequently you need to change out your prefilters. The TDS of your RODI water is important because it should be 0, otherwise your RO membrane or DI resin is stuffed. TDS for freshwater is more for indication-purposes only, there is not a lot that can be done with the information other than knowing if your water is high in ions or not. Purists may wish to seek as low a TDS as possible, but typically the TDS of your water for freshwater is pretty unimportant unless it is very poor (300+). TDS is a measure of the amount of dissolved ions, minerals, salts, metals and other chemicals. Any one of these things can create a high TDS reading, depending on any number of inconceivable factors (bioload, plant life, any decaying plants, high plant growth, feeding habits, time between feeding and testing contaminants in the air, CO2 injection, time of day, ability of your filtration to polish the water (clarity of water), etc etc). Coming from a process engineering background it is very hard to trouble shoot problems with inconsistent readings, and I have practically no faith in the ability to accurately test the TDS of tank water and have it give meaningful results, simply because all of the above factors come into play and can affect the readings from one hour to the next. Trying to infer nitrate concentration from a TDS measurement is like asking a blind man to pick a yellow ball out of a bag of different colored balls. He may know HOW many balls are there, but without the adequate ability he cannot determine which balls are what, and mostly all the balls (or ions/minerals) are harmless. Why not just use a nitrate test kit? They are cheap and accurate. Quote Link to comment Share on other sites More sharing options...
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