Sump level fluctuation

[rickbrown85]

I recently set up a 125 gallon and ever since it has been set up the water level in the last chamber is going down about an inch and a half a day. I was wondering if this is normal because I am about to add an ato and I don't want it to pump to much fresh water in there and mess up my salinity. Please let me know what you guys think.

 

[thegrun]

The last chamber where your return pump sits should be the only section of the sump that experiences water level fluctuations. The amount of fluctuation is dependent upon the size of the return pump chamber relative to your display tank size. I would expect you to have about one to one and a half gallons of water evaporate daily from your tank. What that equates two in inches in your sump depends upon its size.

 

[Timfish]

Evaporation is normal. I've seen 10% of the total system volume in a week in more extreme situations and it can be as bad or worse with below freezing cold fronts than in the summer. With a sump/refugium it will show up in the last section/chamber.

 

[Mrramsey]

Yes that is from evaporation. Make a line at the desired level, then make sure that your salinity is correct at that level. Then only add top off water to the marked level so as not to dilute the salinity.

This would be the same level to set the ATO to once you get it.

 

[rickbrown85]

The last chamber where your return pump sits should be the only section of the sump that experiences water level fluctuations. The amount of fluctuation is dependent upon the size of the return pump chamber relative to your display tank size. I would expect you to have about one to one and a half gallons of water evaporate daily from your tank. What that equates two in inches in your sump depends upon its size.

Thank you for this information. I am having to add about a gallon or so a day, which has ultimately helped me because my salinity was running a little low at 1.020 so me adding straight saltwater daily has got it up to 1.024. I was just worried that my return pump was overpowering my overflows. If you say I should be losing about a gallon a day then this makes perfect sense now.

 

[JMorris271]

Do not add salt water to your tank to replace evaporated water. Evaporated water leaves the salt content behind. Use fresh water for the ATO and salt water only.for water changes only
Condition your tank water to the correct salinity slowly and then keep it there with proper salt water changes..

 

[rickbrown85]

Do not add salt water to your tank to replace evaporated water. Evaporated water leaves the salt content behind. Use fresh water for the ATO and salt water only.for water changes only
Condition your tank water to the correct salinity slowly and then keep it there with proper salt water changes..

I just added it because the salinity was low and there is nothing in my tank because it is cycling. But I got it where it needs to be now and I am just going to add fresh water.

 

[ca1ore]

Do not add salt water to your tank to replace evaporated water.

Unless, as the OP notes, he is attempting to raise salinity levels in the tank - than adding some salt to the ATO reservoir is very effective.

 

[Ron1966]

I use about 1.5 gallons aday in my tank.