Tds, Total Dissolved Solids

[Livewire88]

Hi everyone, I would like some help/advice from some of the knowledgeable members on here about TDS.

I am keeping Gold Rams and want their living conditions to be right, my tap water is high Nitrates, has a high GH, and a high PH 8+
For this reason I am using RO water with a home made Re-Mineral mix which consists of the following; 6 parts Gypsum (aka plaster of paris or Calcium sulphate) 2 parts Epsom Salts (Magnesium Sulphate) 2 parts Reef salt and 1 part Limestone flour (Calcium carbonate)

This was mixed for me by a breeder from a different forum who has been breeding Rams/Apistos for over 10 years. I have been adding enough to my RO water so that the TDS level comes out between 120-130ppm, I have been advised that this would be a good level to keep the Rams at in order for them to live a healthy life. Using this mix my PH reads 7.0, GH reads 5*dh, and Nitrate level is under 10ppm.

The thing is that the tank is planted so I am dosing TPN and Flourish Excel daily, so by adding the ferts and liquid Co2 each day will this be raising the TDS level? meaning I am wasting my time with trying to keep the TDS level low? My aim is to keep the water soft and as clean as possible.

My understanding of TDS is obviously poor and this is why I am asking for some advice/guidance on the matter.

I have been reading info from this link to try and get more of an understanding, is the information contained accurate?

Total Dissolved Solids

 

[ian]

My local water has a Tds of +600! And you can tell, the water clarity isn't great. A Tds of 130 isn't bad, that's about normal for re mineralised ro. Ferts will raise the Tds, but not by to much, this is another reason I like to use purigen, as that lowers Tds. The baked soil substrates also help to lower Tds, the soils like Ada Amazonia and columbo florabase.

 

[TwoTankAmin]

TDS are kinda of a funny thing. I say that because the TDS meters most folks use are not measuring TDS, as you must have read. They are actually conductivity meters which basically translates the conductivity reading into a TDS one. As you have also likely discovered, there is no universal conversion number for doing this. What complicates this process is the fact that as the water temperature changes, the conversion factor also changes. Finally, the two measures do not measure identical factors. That does not mean one can not use a TDS meter to get a pretty feel for their water parameters. Moreover, a TDS meter is perfectly fine for letting one know how well their RO unit is working and when it may be time to replace the cartridges,

I use my TDS meter more to monitor the water parameter changes that are needed to help trigger seasonal spawners. So I am more concerned with the difference between the two readings than I am with their absolute values. This does not mean I am unconcerned with their absolute values as well as the relative changes. Some fish are more tolerant of different ranges than others.

While I do not keep the rams, I do keep altum angels which come from the same river systems. My initial impression of your parameters is that your water may be a bit to high in terms of pH and TDS to trigger them to spawn but not to keep them. However, those numbers may be perfectly fine for the dry season.

Here is an interesting paper on the Orinoco river system. It should give you a pretty good feel for the conditions where the wild rams actually live and spawn. Preliminary Study of Dissolved Organic Carbon in the Orinoco, Bita and Meta Rivers (the paper cover a lot more than just the DOC). Bear in mind that tank raised fish are normally more tolerant of conditions that lie outside their normal range in the wild.

There are a number of studies that you can find via Google. Try doing a search for "Orinoco River + TDS" or "Orinoco River + pH". These will give you a decent idea of the parameters in the wild.

 

[Livewire88]

My local water has a Tds of +600! And you can tell, the water clarity isn't great. A Tds of 130 isn't bad, that's about normal for re mineralised ro. Ferts will raise the Tds, but not by to much, this is another reason I like to use purigen, as that lowers Tds. The baked soil substrates also help to lower Tds, the soils like Ada Amazonia and columbo florabase.

Thanks for the info, my tap water TDS is around the 280 mark, but it was mainly the amount of Nitrates and high PH which made me decide to go down the RO route.

TDS are kinda of a funny thing. I say that because the TDS meters most folks use are not measuring TDS, as you must have read. They are actually conductivity meters which basically translates the conductivity reading into a TDS one. As you have also likely discovered, there is no universal conversion number for doing this. What complicates this process is the fact that as the water temperature changes, the conversion factor also changes. Finally, the two measures do not measure identical factors. That does not mean one can not use a TDS meter to get a pretty feel for their water parameters. Moreover, a TDS meter is perfectly fine for letting one know how well their RO unit is working and when it may be time to replace the cartridges,

I use my TDS meter more to monitor the water parameter changes that are needed to help trigger seasonal spawners. So I am more concerned with the difference between the two readings than I am with their absolute values. This does not mean I am unconcerned with their absolute values as well as the relative changes. Some fish are more tolerant of different ranges than others.

While I do not keep the rams, I do keep altum angels which come from the same river systems. My initial impression of your parameters is that your water may be a bit to high in terms of pH and TDS to trigger them to spawn but not to keep them. However, those numbers may be perfectly fine for the dry season.

Here is an interesting paper on the Orinoco river system. It should give you a pretty good feel for the conditions where the wild rams actually live and spawn. Preliminary Study of Dissolved Organic Carbon in the Orinoco, Bita and Meta Rivers (the paper cover a lot more than just the DOC). Bear in mind that tank raised fish are normally more tolerant of conditions that lie outside their normal range in the wild.

There are a number of studies that you can find via Google. Try doing a search for "Orinoco River + TDS" or "Orinoco River + pH". These will give you a decent idea of the parameters in the wild.

Thank you for the great info, it provided some good reading

Maybe in the future I could try adding less Re-mineral mix to lower the TDS level if I decide I decide to try and breed the Rams, but my main concern is keeping them as healthy as possible. Out of curiosity would you say there is much benefit of having access to a TDS meter?

 

[TwoTankAmin]

I only broke down an purchased one after a friend brought her meter to my fuish room when she came by to borrow about 40 gals of my tap water which seemed to be great for breeding. She actually saved me from a lot of agina as I had been experiencing a decline in spawns. it turns out that my parameters, after a number of years had changed. Without that meter I may not have know what was up. I also found it essential for setting up a tank to receive Altum angels.

On the other hand, for many years I never owned one and if I were not breeding stuff may likely have never bought one. On the plus side mine, (from Hanna) cost me under $30, with an extra bottle of calibration fluid and shipping.