RO water and curing live rock

[spaulr]

Is RO water good enough to cure live rock? The LFS sells both water and Salt water through a dispenser. However, after asking about it I've found that both are RO water. I'm having some production issues with my RO/DI maker (like 2 gallons an hour) and its killing me (apt. water pressure I believe). The RO measured at about 14ppm tds.

For the tank setup I will only be using RO/DI water, but during the live rock curing process (in a 55 gallon tub) I was wondering if I could get away with only using RO water. Any suggestions - other than buying a $85 mini-pump that will increase my RO/DI output to a whopping 3 gallons/hour

 

[paneubert]

I am fairly new here, but I would not see why that would be a problem. You are going to have crazy spikes of ammonia, nitrite, and nitrate. All that cycling will have a much greater effect on water quality than RO vs. RO/DI would.
But of course once you are at the end of the cycle and do water changes to eliminate the nitrate, use RO/DI.

 

[ChrisRD]

Actually, 2 GPH isn't all that bad (that's about 50 GPD). You have to keep in mind that although the membrane in your RO system may be rated for more than 50 GPD (say 75 or 100 GPD), you'll only see that production at optimum pressures and temps. Most of us are not running at optimum pressure/temp so we often see less than the rated production.

As for the slightly impure source water I agree with Paul. IME the decay on/in the rock will generate the bulk of the excess nutrients during curing and I doubt that water will play any significant role by comparison. IME it's best to use a good skimmer (cleaned frequently) and do water changes as necessary to keep nutrients low during the curing process.

HTH

 

[spaulr]

Thanks for your help. That sounds like a plan. I'll use what I have, and then when I do water changes I'll use tap. When I move the rock to the tank I'll be using RO/DI. I'm planning on running my Aqua C ev90 skimmer during the process to help remove all the proteins that build up. However, I guess this raises yet another question for me. I've never had a reef tank, only a FOWLR, so what is the main point of running with RO/DI? I thought it was because of the impurities in tap water - Chloramines, Bromines, and all of the other water purifiers we put in there (not to mention other nasties -heavy metals). Those need to be removed for corals (which is what this tank will be). Is tap water generally high in nitrates, nitrites, ammonia, and phosphates? I swear I learn something new everyday in this hobbie.

 

[ChrisRD]

The difference between slightly impure RO water and tapwater could be significant and personally, I would not use tap for the water changes (unless you've tested your water and know what you're getting into). As you pointed out in your post, tapwater can have all sorts of undesireable stuff in it.

It is certainly possible to run an FO tank (or even a reef) with tapwater, but personally I prefer to avoid it, even in a FOWLR, because I'm not comfortable with the unpredictibility of what I may be adding to the system. For the little bit of extra trouble I prefer the added insurance of using RO or RO/DI.

 

[Anonymous]

>...I was wondering if I could get away with only using RO water.

It is perfectly fine to use RO to make saltwater for curing purpose. In fact, there is not that big of an issue even if you use filtered tap water to make the saltwater, since all the water going to be dumped anyway. For top off and the initial fill of the aquarium, it is a good idea to get the higher quality one, however.