ppm

[sasikan]

how high\low do you keep your ppm in a 20 gallon tank with 4 apistos? how high\low should my ppm be in a 40 gallon tank with 100 about 1 inch growing fish?

 

[Christople]

ppm means parts per million so you have to be referring to something for us to know what you mean. If you are talking about hardness IMO 3dGH (not the same as ppm) which I believe is the same as 51.7 ppm. If about nitrate, 0 would be the best but no more than 20 ppm EVER. Ammonia which is much more toxic should always remain at zero, and will if your tank isn't overfeed/overstocked and fully cycled.

 

[sasikan]

hi and thanks for answering . i am trying to understand my ph\ec\tds hanna hi 98129 meter whenever i measure water from a tank the ec is always about double reading from the tds (ppm) reading . My ph usually runs about 6.5 temp about 78 to 80 f and the ppm (tds) reading is about 200 double that (400) for the ec(us or ys symbol ? ) my fish are doing fine but i don't understand the meter anyone know how to use it and what it means? thanks again jerry

 

[Christople]

Sorry if i am missing the obvious but what is 'ec'

 

[sasikan]

hi could it be electrical current? and if it is what does it mean? on my meter this ec shows a weird symbol (us ) but the u has a line on the left side almost like (ys) if i measure my water coming out of my ro system it reads 0

 

[Christople]

Try turning everything off in the tank let it sit for like five min. then use the meter and if it say 0 ec than it is electrical current.

 

[Mike Wise]

By "ec" you are referring to electrical conductivity. This is measured in Siemens in the metric system. Soft water is typically measured in 'microSiemens' or 1 millionth of a Siemen (µS). TDS on electrical meters cannot directly measure Total Dissolved Solids. You need a chemical test for this. Instead the meter uses an 'average' µS/ppm ratio. On most meters like the one you and I own, it uses 0.5. Therefore you conductivity is 2X your ppm reading. In actuality the ratio can vary in softwater, usually between 0.4 and 0.7. TDS isn't as important to me as alkalinity (carbonate hardness) usually measured in aquariums as °dKH (deutsche Karbonathärte/German Carbonate Hardness). For dKH, I use a chemical test. For overall hardness, I get a 'good enough' idea by measuring electrical conductivity (µS).

 

[dw1305]

Hi all,

.....For overall hardness, I get a 'good enough' idea by measuring electrical conductivity (µS).

I agree with Mike, I also don't bother about trying to measure pH or dKH, even though I have access to lab. grade kit.

Conductivity isn't the most useful measurement, but it is the only parameter that we can measure with any degree of accuracy in soft water.

cheers Darrel

 

[sasikan]

thanks for the answer Mike but now i am really confused! what is my meter telling me when it says (ppm 200)double that for (µS) is this water bad for my fish? aldo the fish seem to be doing great how hard \soft is my water if ppm is 200 or ppm 100 ? is ppm all the fish waste \rotting leaves \organic matter\ left over food ? ps where do you live? i am coming down for a crash course ha!

 

[sasikan]

do i have dirty water if my meter say ppm 100 or 200 or 500?

 

[dw1305]

Hi all,
It is not really a measure of how dirty the water is, but just of all the ions and weak acids in solution. Pure H2O is an electrical insulator (the only ions are H+ and OH-, and they don't conduct). What we call water is a weak solution of ions, the more ions the more electricity it conducts.

Have a look at these:
<http://www.apistogramma.com/forum/showthread.php?9424-How-do-you-check-your-water-hardness-sofness>
<http://www.apistogramma.com/forum/showthread.php?10162-Lowering-Water-Conductivity>
<http://www.apistogramma.com/forum/showthread.php?11838-Water-Chemistry-Osmoregulation-Ionic-Imbalance-amp-pH>
<http://www.apistogramma.com/forum/showthread.php?12164-Sphagnum-moss>
<http://www.apistogramma.com/forum/showthread.php?11247-Another-Peat-Filtration-Question>
<http://www.apistogramma.com/forum/showthread.php?11214-Looking-to-lower-pH-Seachem-Discus-Buffer&p=61157#post61157>

cheers Darrel

 

[sasikan]

lots of info there Darrel thanks!(i have read the first site) the first site at the bottom where it talks about soft to hard water if i understand this, it means the lower the ppm is on my meter the softer my water will be right? so 0 to 100 ppm for the apistos with low ph and soft water demand and 100 to 200 ppm to the less demanding apistos and so on .right?

 

[Mike Wise]

Are you saying that your meter reads 200 ppm TDS and 100µS from the same sample?? Something is wrong either with the meter or the method used. Even an uncalibrated meter should show the same ratio of ppm TDS/µS, since it is only using the electrical conductivity reading to estimate the TDS reading.

I don't use TDS readings, only electrical conductivity. I tend to compare my change water (tap / R/O / modified tap-R/O mix) with that in the aquarium. If the aquarium water is 2X higher than that of the change water, then I definitely change water. The conductivity reading is mostly a reference point to compare change water with tank water. If you have change water with a high conductivity, it can be clean at high readings. On the other hand, if your change water has low conductivity, polluted water can have lower readings than clean water with a high conductivity. Of course low conductivity is important in breeding blackwater fish and I try to get it within an acceptable range.

 

[sasikan]

its the other way around µS readings are about double ppm readings. i think we have the same meter right ? mine is a hanna hi 98129 on the box it says ph\ec\tds\,but when you take a water sample it reads in ppm not tds and it reads µS not ec. these are samples i have just taken: tap water ppm 42 (pretty good right) µS reading 86. my reverse osmosis water is ppm 1 and µS 2 discarded reverse osmosis water ppm 65 and µS 133 i have also taken samples from a couple of tanks a 40 gallons with 100 one inch laetacara ppm 190 µS 396 . a 20 gallon tank with 2 bolivian rams ppm 150 µS 300 .do you think something is wrong with my meter or am i reading it wrong? thanks again jerry

 

[raymond82]

That makes perfect sense, the conversion factor is probably set to ~0.5. I asked a question about this recently and Darrel replied with this very nice link, which clarified it quite nicely to me: http://www.appslabs.com.au/salinity.htm

I think that with the Hanna meter you can manually set whichever conversion factor you want.

it reads in ppm not tds and it reads µS not ec

I think you need to think of it as this: ppm is to TDS what centimeter is to length (and similarly for µS to EC). It's the unit that is used to express the quantity.

 

[Mike Wise]

OK, your meter is working properly. Yes, we use the same meter. I calibrate my meter every month or 2 and make sure the probe is in the stabilization liquid.

 

[sasikan]

ok thanks for the heads up i have never calibrated! i will buy the solution

 

[Mike Wise]

I recommend that you buy the individual 'sachets' instead of a bottle. They may be more expensive, but there is no chance of accidentally contaminating the standards.

 

[gerald]

The conductivity (uS) tells you how much dissolved stuff is in your water that can conduct electricity. It's mainly the salt ions like Na, K, Ca, Mg, Cl, SO4, PO4, NO3, etc. Some water just naturally has higher ion content (and conductivity) than others. Local river water and tap water here in Raleigh is about 150 to 200 uS. It will rise as your tank water ages, due to ions in fish food, plant fertilizers, evaporation, soluble minerals in rocks, etc. Organics (leaves, peat, wood) dont add much conductivity. Hardness (German "General Hardness, GH) is Ca and Mg ions, so you can have high conductivity even in very soft water, if there's lots of other ions and not much Ca or Mg. You could also have high total dissolved solids and low conductivity, if the dissolved stuff is all organic matter and not salt ions. Clear as the Rio Negro?

Oops -- posted my reply before I realized there was a page 2. sorry for the repeat info.

 

[sasikan]

yes thanks i am (getting) some of this now.