is a TDS reading of 800 unusual?

Hi I've noticed that the water at my local fish shop has a far higher TDS level than my tap water even though its only a mile away from home
I have been getting some new fish lately from our local shop, Pets at home
No worries at all with the fish they are always healthy
It's just that the TDS reading from the shop water is vastly different to mine even tho the shop is a mile from our house
Our tap water measures 135 on my meter I add a small amount of dennerle ro mineral to my tank HMA water to take it to about 200
The fish shop water is always about 800 and I measured today and it was 1000 on my meter
It's not a problem although it does take a while to equalise the water that the fish come in
Is this unusual?

Hi all,
Conductivity meter are pretty robust, so I think it will be right. It has probably got salt (NaCl) in it. You only need a relatively small amount (of any soluble salt) to raise the conductivity massively. I think about one teaspoon of NaCl in 10 gallons will raise the conductivity by about 300 uS.

P@H are an American company, so this may well be relevant: "Water Chemistry: Osmoregulation, Ionic Imbalance & pH" in "The New England Cichlid" A NEW ENGLAND CICHLID ASSOCIATION PUBLICATION April 1, 2011.
<http://www.tbas1.com/Exchange/The%20New%20England%2011.pdf>.

Have a look at this post as well. <http://www.plecoplanet.com/forum/showthread.php?t=3480>.

They are well worth a read.

cheers Darrel

Thanks Darrel that explains it
thanks for the links as well:clap:
Think you are right they probably added a small amount of salt as a preventative
In the first link its uncanny finding a higher TDS in the fish shop water than the natural tap water caused by added salt !
apparently large changes in TDS cause an imbalance in osmotic pressures in the fish which can damage the fish and cause stress

I wonder if this is why sometimes people have apparently healthy fish die within a day or so after buying them at the shop and putting them in their tank

I measured the fish shop water (from the bag the fish came in (I think they add stresscoat to the water when they bag them up))out of interest really a couple of years ago as then I was using R/O water and didnt want the fish to be stressed

I now use HMA which should be the same as tapwater and I would have expected the shop water to be similar to mine as I live very close to the shop

not saying anything against the shop they are very good and do try to help

Hi all,
I can't see any use for salt for soft-water fish, but Neil at "Pier Aquatics" uses it. Have a look at these: <http://www.planetcatfish.com/forum/viewtopic.php?f=6&t=32126> & <http://www.planetcatfish.com/forum/viewtopic.php?f=2&t=35797>
Neil is "Sojapat".

cheers Darrel