anyone good at maths ?

[daztiz]

while everything is running, if i drip out 25 litres of water from the display tank and drip in 25 litres of new water in the sump , how much new water am i taking out ? 125 litre tank and sump combined. the reason im asking this so i can acclimatise and water change at the same time . thank you

 

[Jon Fishman]

Depends how big the drip is? You got a little hose???

 

[BZOFIQ]

Based on my previous calculations the difference between removing and replacing 25 gallons vs dripping it in and dripping it out is fairly negligible.

In the first case you'd be exchanging 20%, it the latter probably 15-16% if I had to guess.

 

[mcdrichj]

You would be doing a 20% water change. you cant really think bout it as taking "new water" out because it all goes into solution. It would be slightly less effective then doing a regular water change.

 

[Jeto2004]

This is a question of dilution over time. Does the drip out contains substance of the drip in. So location of drip in vs drip out is important to. Also of timing how many drips per min. With all of this assumption worked out one could come up with an equation to solve this problem. However I think for simplicity reasons I think you could say you changed 25L of water in the end.

 

[Greybeard]

I was doing auto water changes for about a year. Worked great... until it didn't.

I had the system set to remove water from my refugeum, 1st compartment of my sump, and add it to my return pump compartment. I'd estimate that very little 'fresh' water was being lost.

Oh... my DOS pump, the one pumping new salt water into the tank, stopped. The one pumping water out kept right on dosing so. Auto top off did what it is supposed to do, and refilled with fresh water. I didn't notice until my corals started looking bad... salinity was 1.012. I highly recommend a Salinity probe with an auto water change system.

 

[daztiz]

thank you for all your replys , all very helpful , ( john i dont think its the size of the hose that matters its how you use it , ha ha ) yeah main thing is to turn auto top up off , and dont have to heat the new water either , brilliant