I posted this in another forum topic (it was a little off track) so I thought this is worth a discussion in itself.

An example, I have a 60L TB tank that runs at approximately 150TDS. If I was to take out 10-15% (9 litres) of water and change this with RO water how much salty shrimp should I use with the new RO water to maintain 150TDS in the tank. Reason I ask this is I have heard people mix salty shrimp to a TDS of 150 in the new RO water of say 9 litres and when dripping it back in they get a huge swing in TDS readings.

This would obviously lead to a much higher TDS when the water change has been added and severely stress the shrimp?

Do we have a guideline for how much salty shrimp you should add in to meet current tank TDS? 

I aim for TDS of 110 - 125 in my change water. TDS pen comes in handy here to measure the change water before adding it in the tank.

Once added to the tank it should maintain a 140-160 TDS. The main tank will always have higher TDS due to foods being added, and water evaporation, and the constant production of nitrogenous waste.

Thought so and this is what I do, just seems people might add the same TDS to the change water to the tank water and this could skyrocket the tank water to a larger TDS.

My tap water has a 195 TDS lol

5 minutes ago, NoGi said:

My tap water has a 195 TDS lol

Wow. I wonder what's in your tap water that make it so high. It's certainly not just Ca & Mg.

Mine is about 80 the last time I checked a few months back.

I should test it again to see if it was an anomaly.

JayC I'm in Adelaide and my tap water can be 300!!!!

I always mix and test my RO water in a bucket and make sure it is less than the tank water so if my tank sits at 150 my water is mixed to approximately 130 . I also check the temperature and make it as close to the tank as I can- a laser temp gun makes that easy work. I use a jug and slowly pour the water into my tanks- I do it to all 13 and have done it that way for 3 years. my tanks are overflowing with all sorts of babies! 

All my tanks are treated the same , have the same substrate etc but at the end of the week there is usually a 10 point difference between them- some stay 150-155 others go to 160. I would say it's to do with the population in each tank and the amount of food I put into them accordingly. I also still use something like Boss booster each week, mironecton fortnightly and Beta-G -when I can get it. The TDS never fluctuates much more than 10. I also add pure RO if there has been a lot of evaporation -I only have half my lids on in summer instead of full coverage to help keep the tanks cooler.

Bee Shrimp Mineral GH+ - Minerals and trace elements

Dosage
Use Bee-Shrimp Mineral GH+ to re-mineralise RO water, rainwater, fully desalinated water etc. to reach a total hardness of about 6 °dH and/or a conductance of about 200 +/- 50 µS (Microsiemens). For this purpose, an evenly full measuring spoon (about 3 g) to 20 litres of water is sufficient.
Measuring spoon enclosed

http://www.saltyshrimp.de/english/beesalt_bee_shrimp_mineral_gh_plus.html

Shrimp Mineral GH/KH+ - Minerals and trace elements

Dosage
Use Shrimp Mineral to re-mineralise RO water, rainwater, fully desalinated water etc. to reach a total hardness of about 6 °dGH and/or a conductance of about 300 +/- 50 µS (Microsiemens). For this purpose, an evenly full measuring spoon (about 2 g) to 10 litres of water is sufficient.
Measuring spoon enclosed.

http://www.saltyshrimp.de/english/shrimp_mineral_gh_kh_plus.html

36 minutes ago, ineke said:

I'm in Adelaide and my tap water can be 300!!!!

I'm part way through writing an article on TDS.

In my research 500ppm TDS is considered contaminated water. 1000ppm TDS is unfit for drinking.

 

300 TDS is getting close to water that is considered contaminated.

 

Next time some one from Adelaide says they are having issues with their shrimp, remind me to ask them if they are using tap water. 

I was amazed when I had such high readings , I haven't tested the tap water for 12 months or more as I use RO now and a pura tap for our drinking water. I think I might survive!

i can beat you all, my highest TDS of tap water was 380+

What bore water???

65 from the tap for me.

I typically get around TDS 95 from the tap but the only shrimp I use it for are the hardy natives and cherry culls. Anytime I've used it with more sensitive shrimp (CRS, high bred cherries or tigers) I've gotten random mass deaths following some water changes. I use a carbon filter but it appears there is something nasty in the water sometimes.

8 hours ago, fishmosy said:

I typically get around TDS 95 from the tap but the only shrimp I use it for are the hardy natives and cherry culls. Anytime I've used it with more sensitive shrimp (CRS, high bred cherries or tigers) I've gotten random mass deaths following some water changes. I use a carbon filter but it appears there is something nasty in the water sometimes.

copper pipes in the house?

9 hours ago, shrimpaholich said:

copper pipes in the house?

Yes, so copper is a possibility. However I think its more likely the carbon filter just gets old and stops filtering out all the chlorine/chloramine, particularly after heavy rain events when the water supplier doses these quite heavily.  

I wonder how much trouble copper pipes actually cause? My house was built in the 1960's and has copper pipes which I doubt have been replaced and although I do use RO water now I used treated tap water previously for about 12 months. If the water isn't sitting in the pipes but just running through it would they actually leach much copper?