What TDS should I aim for?

[sciencefiction]

I think you are going about this the wrong way round. The researchers are trying to find the factors within the physiology of Cardinal Tetra (<"Paracheirodon axelrodi">) which allows them to survive in the acidic, mineral poor black-water, they aren't adapting to it, they are adapted for it.

Thanks Darrel. Yes you are right. What I wanted to say is fish can adapt. I am not saying black water species can adapt to hard water. Some fish have the capability, others don't.
I overlooked that cardinal tetras are actually adapted to it. I never kept these fish. The corydoras schwartzi was a better example

 

[sciencefiction]

There is an explanation of why older snail shells whorls erode in this thread <"Nerite Snails in high tech..">. I think for the vast majority of people water with a reasonable amount of carbonate buffering is going to be preferable, and make aquarium management easier etc.

This doesn't answer my problem though. What would you suggest to solve the shell erosion? I've posted my stats earlier. At least that's what the tests read but I've no doubt I have hard water coming out of my tap and it reads the same in the tank.

 

[sciencefiction]

Some "blacker" water species like clown loaches do quite well acclimated to harder water too.

Clown loaches come from very acid black water habitats from Borneo and Sumatra.
Many people keep them in soft water(RO mix) trying to mimic the conditions. If you search for "clown loaches black spots" you'll find numerous threads about this black/brown spot "disease" which is actually caused by a fast TDS drop(people adding freshly made RO mix water to the tank). The water is probably swinging the Ph too. You would imagine them thriving in acidic conditions but as many other fish, stability is more important. I would imagine trying to keep any black water species is a challenge if they can't adapt to more "stable"/harder water tanks.
Here is an example pic I saved, with clown loaches kept at a Ph of 4.5, Kh 1 with an ever dropping Ph. Some don't survive these constant fluctuations they are subjected to in a tank. The issue seems to be resolved when the water is "stable" regardless of Gh, TDS, Ph, Kh, etc..

Other tank mates in the same tank:

And my clown loaches in hard but stable water.

I rescued this one a year and a half ago looking like this when I got him.

Now

A video of him now. I dare say he's thriving despite me being told a few times I should keep them in soft water. But my stats are rock solid and don't fluctuating one bit except for the TDS rising by the end of the week but I dose some ferts too.

 

[Andy Thurston]

Soft water species are capable of utilizing low calcium/magnesium availability in the water. However, being the sceptic I am, one needs to know whether those people's fish lived their full life spans in whatever conditions they were kept in

re: the clown loach.
They do seem to be looking quite healthy but are you going to live long enough to see if they reach their full lifespan potential in harder water?

 

[sciencefiction]

re: the clown loach.
They do seem to be looking quite healthy but are you going to live long enough to see if they reach their full lifespan potential in harder water?

Yes, that's a valid question that gets thrown in a situation like this every time, which one I will only be able to answer in 20-50 years if I am alive myself. I don't know if they'll reach their full life span kept in this water. It's yet to be seen. There are very few accounts of keeping these fish alive for more than 20 years regardless of the water in which they were kept. I can't do complicated tests on my fish to know if they are "adapted" to my water. But I know non-thriving fish develop all sorts of unusual "diseases" if not happy.
All I can say is based on colours, development and behaviour mine seem quite healthy for now. Time will tell. I maybe wrong.
If that sickly looking clown was not happy in my water conditions, he wouldn't have improved over time. He would have gone worse. It took him about 6 months to "improve".

 

[LondonDragon]

Could you use TDS as an indicator for when you need a water change? I have noticed that it increases over the week, tested with higher levels of feeding and it increases quicker. My TDS comes out of the tap at 550-580, in the tank after a water change it adds another 100 or so. By the end of the week this usually increased to around 750-800, and resets back to 650-680 after a water change. Thoughts?

 

[dw1305]

Hi all,

Could you use TDS as an indicator for when you need a water change? I have noticed that it increases over the week, tested with higher levels of feeding and it increases quicker. My TDS comes out of the tap at 550-580, in the tank after a water change it adds another 100 or so. By the end of the week this usually increased to around 750-800, and resets back to 650-680 after a water change. Thoughts?

Yes, that is really what I do. I just mix our tap water (about 17dKH) with rain water to give about 100 microS. Because I don't add nutrients regularly, but I do a lot of small volume water changes, after I've fed the plants, values will return to the ~100 microS level fairly quickly.

cheers Darrel

 

[parotet]

I guess if you are an EI user things may be more difficult. I learnt from Darrel the use of the TDS (as he says, cheap equipment, no maintenance, fast reading and quite reliable measuring) but I add daily potassium sulfate and micro mix... Dosing that lean I end up the week with 200-300 microsiemens more and I believe a significant part of them is due to the salts added. I have not enough skills to calculate this but it seems to me that adding 30 ppm of NO3, 5 ppm of PO4, 30 ppm of K and micros will rise your TDS quite a lot, isn't it?
I think it can work in lean dosing tanks as an indicator of.... Of what exactly? Metabolites?

Jordi