water evap

hi, just a quick question

I've read a lot about people topping up their reef tanks with ro water no salted.

I was wondering how you top up after a day or week of evaporation?
Ro Water?
Salted Ro water?

 

Salt does not evaporate. Only add fresh water when topping off.

 

Ro water only. Always.

The only time you should add mixed salt to your tank is if you're replacing salted water you took out because of a water change. Or if you're trying to get your salinity higher.

 

I recommend an automatic top off (ATO). If you don't have a controller AutoTopoff.com has good deals on their systems and you don't have to worry about wiring anything up. Top off with fresh RO/DI only.

 

A Week is quite awhile before doing a top off. My schedule is every other day I top off with conditioned Pur water from my tap because I do not have a RO/DI filter yet. What I do is take a 1gal zip lock bag, add .5gal of fresh water,then fill the rest with tank water and sit it in the tank for an hour or 2 to warm up to the tank's temp. I usually do everyday in the winter because its drier around here (CT). Also adjusting the skimmer to pull in thicker detritus can sometimes help reduce the amount of top off needed.

 

Smackrock, unless you have a VERY small tank, 1/2 gal of water added directly to the system wont cause a noticeable change in water temperature. I add 2+ gallons of water per top off to my 58+sump per day, about 1g at a time, it doesn't register on the thermometer.

And even if you have a 5 gallon pico tank adding 1gal of 70 degree tap water to a 75 degree tank will only shift the temp 1 degree or so, hardly a big concern.

As long as the water is chemically suitable to add to the tank, and within let's say... 20 degrees of the tank temp, you should be just fine.

 

Always use RO water to replace water that has evaporated. It is better to add a little every day than to add a lot once a week.