# Does EI Fert Dosing Affect TDS?



## forever (1 Jul 2015)

So before i started on the Micro/Macro my TDS was around 250, its now after 4 weeks of using the auto pump dosing upto 310, thats a day after a water change.. 
Should i be concerned? fish and plants all look good..


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## Marcel G (1 Jul 2015)

1) *IF* Total dissolved solids (TDS) is a measure of the combined content of all _inorganic _and _organic _substances contained in the aquarium water.
2) *AND* Fertilizers add _inorganic _substances into the aquarium water.
3) *THEN* ... what do you think?
Yes, you are right ... adding fertilizers into your tank *WILL *affect TDS (it will increase its value).


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## forever (1 Jul 2015)

Thanks for the reply, given that i have not read anywhere what a safe band is for TDS, or even a optimum value...


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## Jose (1 Jul 2015)

forever said:


> Thanks for the reply, given that i have not read anywhere what a safe band is for TDS, or even a optimum value...


.
If you are doing 50% water changes then TDS should fluctuate between an after water change value (a) and a before water change value (b). It wont keep climbing unless you  do top up ups with tap water, it will go on climbing but very slowly then. Dont worry about it unless you have highly sensitive shrimp.


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## parotet (1 Jul 2015)

forever said:


> Thanks for the reply, given that i have not read anywhere what a safe band is for TDS, or even a optimum value.


There are no recommended values unless you want to keep fancy shrimps, which are quite sensitive. Plants can be grown with any number from low to high TDS, I have grown plants successfully with 1000+ microsiemens and I am doing it right now with 400, but you will find people growing plants with just 100 microsiemens. In my experience, I find "easier" (less algae problems, plants look best especially mosses, CO2 not that critical, etc.) to grow plants in the low TDS range (well, I have only tried the 300-400 range compared to the +1000, which is probably considered a medium TDS value rather than a low value).

Jordi


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## forever (1 Jul 2015)

Thanks all, just sensitive as i keep discus in my tank.. Everything seems to be doing well, bar the cory's digging up the plants, this is less now they have started to root strongly.


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## Dantrasy (1 Jul 2015)

I aim for 120 tds and use rodi. wc if it goes over 200. 
this way all my tanks are ready for shrimp should i pop some in.


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## dw1305 (1 Jul 2015)

Hi all, 





forever said:


> Thanks for the reply, given that i have not read anywhere what a safe band is for TDS, or even a optimum value...


 There isn't really an optimal level.

*TDS and conductivity*
A TDS meter doesn't actually measure "ppm Total Dissolved Solids", as "Ardjuna" says it is a measure of the total compounds in solution, and you can only measure it by taking a known weight of tank water, and evaporating it to dryness. The residue that remains is the "TDS" expressed as ppm. 

A useful concept to visualise TDS is to think of "evaporating to dryness":

Sea water, in that case you would mainly get salt(s), which were in solution as inorganic ions.
A cup of tea, where you would mainly get organic compounds like sugar, the de-natured proteins from the milk and the tannins from the tea.
*Conductivity*
The TDS value we are given is from a measure of the all the ions in solution, with a conversion factor applied. We measure the ions in solution using the electrical conductivity of the "water" in micro Siemens. 

Usually the conversion factor used is 0.64, so 100micros = 64ppm TDS. 

Pure H2O is an electrical insulator, and doesn't conduct electricity, water from an RO unit will have very few dissolved salts and will have a conductivity value of ~5 microS, hard tap water saturated with calcium carbonate would be ~500 microS and  53,000 microS for sea water (mainly Na+ Cl-).  

*TDS Range*
I'm low tech.,  I keep _Apistogramma_ and I aim for about ~100 microS. I came to this value the same way as Jordi, I measured the conductivity when the fish had spawned successfully, and the plants <"showed some growth">, and eventually I found that these values lay in the 60 - 120 microS range. 

If you are using EI your values will be much higher (plants can only take up nutrients from solution as ions).





Dantrasy said:


> I aim for 120 tds and use rodi. wc if it goes over 200.


 I think that is probably a good approach for Discus as well. This would be a lower dosing rate than for EI.

cheers Darrel


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## forever (1 Jul 2015)

Thanks all, so pre EI and Co2, the water was 250. Discus have been kept and bred in this for a number of years, its now 310, does not really move that much until water change day and it goes down to 240 my tap water is at 180..


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## dw1305 (1 Jul 2015)

Hi all,





forever said:


> Discus have been kept and bred in this for a number of years, its now 310, does not really move that much until water change day and it goes down to 240 my tap water is at 180..


That is the main thing.

I don't think it is a problem. If it really climbed you would just have to up the volume, or frequency, of the water changes.

I use rain-water for the tanks, and our tap water is a very clean, hard supply from a deep limestone aquifer, so I can change the mix of rain-water to tap to raise or lower the TDS.

cheers Darrel


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## Martin in Holland (1 Jul 2015)

I had the same "problem" when I was using EI, my TDS even went over 400 with a tap water TDS of only 60. I couldn't get it down even with 2-3 water changes per week, so I gave PPS-pro a go and now it's stable at 150-180 even with 1 water change per week.


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## parotet (1 Jul 2015)

Martin in China said:


> I had the same "problem" when I was using EI, my TDS even went over 400 with a tap water TDS of only 60. I couldn't get it down even with 2-3 water changes per week, so I gave PPS-pro a go and now it's stable at 150-180 even with 1 water change per week.


Not exactly this (although I now dose N and P very lean), but one of the benefits I have found when using low(er) TDS water is that one 30% weekly WC is more than enough to keep my tanks on the top, while when I was using high TDS (combined with EI) I needed 2x 40-50% weekly WCs.

Jordi


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## JohnC (2 Jul 2015)

the highest tds i've seen on a freshwater tank was 2500 ish (if i remember rightly). done by accident as i supplied a friend with EI solutions and he assumed the extra magnesium dose I gave him to compensate for the lack of mg in the trace solution was daily.

his shrimp died but the fish were ok (although i'm thankful we caught it when we did). another result was the some mutations with a mini java fern species I have been using for years turning full size and forking. I've been told by a friend of a friend of a biologist that high magnesium levels can cause DNA corruptions and mutations through generations.

The tank is back to 200 ish tds now thankfully.


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