Using ro not ro/di water

[undertaker777]

I bought a ro buddie thinking that is would be sufficient enough for a reef tank. However I've learned that that's not the case I need the DI also.
I'm three days into my cycle, and now have a BRS ro/di system with pressure gauge and do DDS tester. When it comes in should I do a 50% water change or should I wait for my tank to finish cycling first?

 

[undertaker777]

Dual TDS tester*

 

[anthonys51]

doing a water change during a cycle will cause the cycle to be longer, wait till the cycle is over then do the water change.

 

[NYCBOB]

Do the water change. It can only help dilute whatever contaminate u have in their current water.

 

[jcjrogers]

When I ran tanks years ago, I had separate RO and DI units. The DI unit was inexpensive, and I just plugged the RO into the DI. The biggest problem with running the DI by itself was that the cartridges discharged pretty fast. However, after first running through the RO first, the cartridges lasted a lot longer. I imagine these DI units are still available.

 

[PatW]

In my BRS RO unit the water coming out of the RO membrane is 2 tds. It goes into the DI and comes out at 0. My tap water is about 120. I have heard of people successfully running Reef aquariums right off of tap water. In these instances the tap water is always low tds. I would think that your RO water is probably low in TDS. Using 0 tds is better. Given some time and normal water changes, your system will end up being like it was RODI from the get go.

There is a peace of mind issue here. If the idea of having low tds water in your tank bugs you, do enough large water changes to give you some peace of mind.