Still very confused about KH and active substrates

[Iwagumi_Scaper]

Just tested my tank water after a week of ferts EI dose at 200% and 560ppm

Quick question about this then. TDS is going to drift up over time if I just use straight tap water right? Normally I would correct it by mixing up RO with Salty shrimp salts to a lower TDS to bring it back down. Do I just mix my tap with RO to the same effect to maintain the desired TDS/KH/GH?

 

[dw1305]

Hi all,

Do I just mix my tap with RO to the same effect to maintain the desired TDS/KH/GH?

Yes, that is the one, you don't actually know what the ions are, but you've added dKH and dGH from the tap water and nutrients via your fertiliser addition.

If you have 400ppm TDS and you mix that water 50:50 with RO your new water is 200ppm TDS, with half as many ions as it had before.

Conductivity isn't the parameter that you would really like to know, but I like it because it is a linear scale between RO water at ~10 microS (~6 ppm TDS) and full salinity sea water at 53,000 microS, and you can just dip the meter in and get an instant and accurate reading.

cheers Darrel

 

[Zeus.]

TDS is going to drift up over time if I just use straight tap water right?

Yes Just like it does in rivers and lakes from rainy days to long dry summers. Even if you use RO water your TDS will increase esp in High tech tank with ferts being added daily, more so when added x2 EI levels like myself

 

[tam]

The TDS will be higher than the tap when you add a lot of ferts, but if you do 50% water changes weekly it should stabilise so the amount it raises over the week is reset by the water change. You dont need to adjust your refill waters TDS to do that, although it will work better if you do any top ups with straight RO.