RO water for top off? Distilled?

Mark9 · 09/23/2013, 07:21 AM

I bought a DI filter to add to my RO unit, but I won't get the fittings to connect it for another week or so.
Can I just use RO water for top off in the meantime?
What about distilled water?
Or should I just wait until I have the DI running?
I'm still cycling, so no fish yet.

MondoBongo · 09/23/2013, 07:53 AM

you should be fine to top off for a week without the DI installed, unless for some reason your RO unit is outputting high TDS.

i actually started my tank with just RO water, and converted to a RODI unit after about 6 months to help combat some of the algae problems i was having at the time.

tldr; i would just go ahead and top off with the RO and not think twice about it.

thegrun · 09/23/2013, 08:09 AM

I would either use distilled water or wait until the fitting arrives. If your salinity goes over 1.028 I would purchase and add distilled water and not wait for the fitting.

09/23/2013, 07:21 AM	#1
Mark9 Registered Member Join Date: Aug 2013 Location: Atlanta Posts: 2,497	RO water for top off? Distilled? I bought a DI filter to add to my RO unit, but I won't get the fittings to connect it for another week or so. Can I just use RO water for top off in the meantime? What about distilled water? Or should I just wait until I have the DI running? I'm still cycling, so no fish yet.

09/23/2013, 07:53 AM	#2
MondoBongo Obligate Feeder Obsessed Join Date: Oct 2012 Location: Pittsburgh, PA Posts: 4,061	you should be fine to top off for a week without the DI installed, unless for some reason your RO unit is outputting high TDS. i actually started my tank with just RO water, and converted to a RODI unit after about 6 months to help combat some of the algae problems i was having at the time. tldr; i would just go ahead and top off with the RO and not think twice about it.

09/23/2013, 08:09 AM	#3
thegrun Registered Member Join Date: Dec 2008 Location: Garden Grove, Ca Posts: 17,023	I would either use distilled water or wait until the fitting arrives. If your salinity goes over 1.028 I would purchase and add distilled water and not wait for the fitting.