Newly mixed saltwater filmy. New RO/Di unit?

Discussion in 'More Saltwater Aquarium Topics' started by DearPrudence, Jan 7, 2013.

  1. DearPrudence

    DearPrudenceValued MemberMember

    I just got a 50 gpd Coralife Ro/di unit for Christmas. I have it all hooked up correctly, ran, and trashed more than the 10 gallons that it suggested. After doing that I mixed my water as I always do with RedSea Coral Pro salt (1/2 cup per gallon) with a pump and heater in a Rubbermaid. When I opened the bin up about 30+ hours later (I was too busy to do it after 24), there was a white film all over the bin, pump, and heater. It easily rubbed off and clouded up the water, which was pretty clear aside from the film on the bin. I trashed it all and scrubbed the bin and equipment. The only thing that changed was the RO water (I used to use tap), the rest of the process was exactly the same. The salinity was also still measuring 1.025. The only other weird issue I've had is one time my bin turned brown, but the water was still okay and I used it in my tank without problems. What happened and how do I fix it?!
    Last edited: Jan 7, 2013
  2. JessiNoel21

    JessiNoel21Well Known MemberMember

    It was the RO/DI reacting to the taps water residue that was more than likely still in the bin. I had it happened to me all you can due is let it run its course. It might take a few batches but it will go away the water will be fine to add to the tank just make sure your skimmer is dialed up to skim it off. Or you can take a fine filter floss and a stainer and pour the water over it into your bucket or whatever you use for your water changes.
  3. ryanr

    ryanrModeratorModerator Member

    Could be Jessi, could well be :)

    I get a film in my mixing bucket too.... I use Seachem Salinity now... never happened when I was using IO Reef Crystals.

    I think it could also be residue from salt mixes. RO/DI is pure water, and sometimes, because most everything else is heavier, it floats to the top (like an oil slick). It may be that some salts are higher in Mg or something, and a film develops, but once it's all mixed, it's clear as day.

    I don't think you have anything to worry about, I think it's pretty normal for RO/DI salt mixes.
  4. OP

    DearPrudenceValued MemberMember

    Thanks! I'll just DIE if I kill my tank.
  5. OP

    DearPrudenceValued MemberMember

    Well I made a new batch and that was clear. I used it and all my fish and corals are happy this week. Then I rinsed out my rubbermaid and pumps while it sits in between making water, only to find it has that white residue (dried) all over the place again. Very weird.

    Also, my tank used to be at about 8.0-8.2 (can't remember which), and now it's reading more like a 7.8. Is it normal for RO water to have such low pH with the same salt and supplements being used? What can I do to fix this? I have some Seachem Marine Buffer, should I use that? Maybe boost it up and hopefully it'll stay up?