Smart ATO top off in planted tank

[SDIESEL77]

If you want to do it "100% properly" you are supposed to use RO water so as to not add more "salts" (eg hardness), as adding tap water will increase the accumulated "salts" in the tank.

However in the end, if doing frequent weekly water changes, and adding weekly say 6 litres tap water a week in 900litres is only about 0.5% so, b*gger all really.

The tank is actually 205L but indeed I'm not ready to use RO water.
I'm doing 50%-70% weekly water changes

 

[Andrew Butler]

If you want to do it "100% properly" you are supposed to use RO water so as to not add more "salts"

I did in my marine but I don't think it's worth the hassle for what little you introduce compared to Saltwater.

 

[zozo]

Is it normal for a 200L tank

I'm 0.5 litre less with a 125 litre setup.. That's a 110 litre open top tank with a 15 litre open top planted sump. So i guess it's pretty normal to be between 1 and 2 litres of water a day. I easily could go for a auto top off in the sump regarding water connection, but unfortunately i do not have easy access to drainage.. So it's a no go for now.

Another thing you could take into consideration is building a sump.. Than the water level in the tank stays as is, but it lowers in the sump instead. This way you can play a little with volumes and reduce topping it off to once or twice a week.