New RODI question

[Bryan47]

Hope everyone is having a great holiday weekend!
Got my RODI in from BRS yesterday. My question is what is the best way to change out the water? Should I do a few big water changes ? Lots of small ones? I don't have a stand alone tds meter to monitor the tds in the tank.

 

[mike007]

Are you do salt or fresh water tank?

 

[Bryan47]

Salt

 

[mike007]

I really don't understand what you are asking. You do not use a tds tester on your tank water only the ro water that comes from the ro unit. It looks like yours has one on the unit. As far as water changes most people do 10%-15% with premixed salt. Ro water should be used as top off water when your level gets low.

 

[Bryan47]

I would use the tds meter to get an initial reading on my tank and then see how close I can get it to 0. Currently it has tap water with prime used. So if I got a tds of 100 and did a 50 percent water change it would stand to reason the new tds reading would be 50 if I did another it would be 25 and so on. Eventually I would want to get to 0. I just want to know how much is a safe bet to start with.

 

[DarkTang]

You don't use tds water on your tank... you want 0 tds on ro water only... your tank will never have 0 tds... if your tank has 0 tds that means it's just plain ro water and no salt or anything else in it...

 

[drsalomon]

Tds meter in tank is of no use because salt water will mask everything. Just start using ro water for topoff and fresh makeup salt water.

 

[saltyphish]

I think you are saying you have been using tap water for water changes and are now switching to a ro/di unit. You want to know how much water to change to remove the existing tapwater. There is no simple equation here. If you are running a saltwater tank then a reading of the tds in the tank is useless since you add the salt mix which will show as tds. So how to remove the tap water in your tank? You can start out with a 50% water change if you are concerned about anything that was in the water. While it will not remove all of the older water it will dilute it. You continue to do weekly water changes of 20-30% and over time it will be gone. What is the concern with the tap water you were using? Are you having a algae issue? Are you showing excess nutrients when you test?

 

[argi]

Just to reiterate what others are saying, use the TDS meter to measure the purity of your RO/DI water, not your tanks water. In reality unless you do a 100% water change there will always be some tap water in the tank, you will just dilute it more and more. But you shouldn't need to get rid of it 100%. Just start using the RO/DI water to make up saltwater and to use for topping off from evaporation.

 

[phillrodrigo]

Yea the tds in your tank would be so high because it would read all the salt so it really doesn't matter. Just make sure the water coming out of the rodi is 0. Running larger amounts are better than multiple smaller ones. I try to make my water once a week

 

[Bryan47]

I see, thanks guys!!!