Aquarium Forum

  · Tropical Fish Home
· Fish News
· Aquarium Forum
· Buy & Sell
· Calculators
· Equipment reviews
· Free Aquarium Ebook
· Feedback
· Link to us
· Photo gallery
· Plant species
· Tropica Plant DB
Tropical fish species
· By Common name
· By Scientific name
Tropical Marine fish
· By Common name
· By Scientific name

        Via paypal

  · African Cichlids
· Algae Control
· Aquarium Decoration
· Aquarium Resources
· Aquatic Plants
· Barb Fish
· Betta Fish
· Breeding Fish
· Catfish
· Central American Cichlids
· Cichlids
· Clownfish
· Corals
· Corydoras Catfish
· Discus Fish
· Dwarf Cichlids
· Fish Diseases
· Frogs and Turtles
· Goby Fish
· Goldfish
· Gourami
· Invertebrates
· Jellyfish
· Killiefish
· Lake Victoria Cichlids
· Livebearers
· Malawi Cichlids
· Marine Aquariums
· Marine Aquarium Fish
· Other Fish
· Pleco
· Predatory Fish
· Photography
· Pond Fish
· Responsible Fish Keeping
· Rainbow Fish
· Shark Fish
· South American Cichlids
· Tanganyika Cichlids
· Tetra Fish
· Tropical Fish Food
Results 1 to 4 of 4
  1. #1

    Default Reverse osmosis and testing for pH/Hardness.

    0 Not allowed!
    Just getting a few things ironed out before I get the RO unit installed...

    Trying to future proof myself a bit so have decided to store my RO water in something like a large water butt. I'll just systematically fill it up every few days from the RO tap. I'd love an automated system but living in a rented flat I can't get away with drilling holes. Unit will be underneath the kitchen sink and due to design there's just no way of rigging up rent-safe piping unfortunately.

    First question is, how long can the water be left standing? I know that in terms of safety to drink you can leave water in a closed container for decades before it's actually bad for you. It'll taste bad, but it's still safe. However not sure how this translates to aquarium water. Would water be OK to be left standing for a week in a water butt? I'm assuming it will be fine, but just wanted to double check.

    Question the second was about re-mineralising. Second reason I wanted to go for 'mass storage' was the ease of re-mineralising. Instead of doing it bucket by bucket I can just fill the butt, re-mineralise the entire thing and know there's zero variation in water conditions. However, what is going to be the easiest way of testing the parameters of the water?

    I'm thinking a digital pH meter because as I understand it, the pH will raise as the hardness does when you re-mineralise. I'm thinking from the stand point of if I have a half empty butt of re-mineralised RO... topping it up with pure RO and then re-mineralising again is going to be fiddly to get right if doing it via calculations and weight. I also don't trust my eyes when it comes to using the liquid test kit, don't see the colours all that well. If I could use a digital pH meter it'd just be a matter of filling the butt back up, taking a reading, then just gradually adding the minerals until the pH is the same as it was before and the same hardness as well?

    Would this be an acceptable method of bringing the RO water up to scratch? I'm a little sketchy on how reliable it'll be to use pH to measure hardness as I know the two aren't precisely indicative of each other and that's the main concern really.

    Thanks for your help as always. Looking forward to the day I'm not such a newb and can actually contribute to the forums!

  2. #2


    0 Not allowed!
    I often have RO water sitting in a large 35 gallon for up to three weeks before it gets used. Been doing that for a few years now without any problems.

    Can't really help you with your other questions as I have never used those types of additives before.
    If you take your time to do the research FIRST, you can successfully set-up and keep ANY type of aquarium with ease.
    "Not using a quarantine tank is like playing Russian roulette. Nobody wins the game, some people just get to play longer than others." - Anthony Calfo
    Fishless Cycle Cycling with Fish Marine Aquarium Info [URL=""]

  3. #3


    0 Not allowed!
    I assumed that would probably be the case, just wanted to double check.

    I'd be "re-mineralising" with . If that makes any difference. Probably should have noted that, might make a difference.


  4. #4


    0 Not allowed!
    I have an RO/DI unit and make about 35 gal a week for my freshwater tank. I don't use it all (use about 25-30 gal) and the rest is fine (pH and GH remain stable) till the next week. When new water is added to the old I adjust my pH and GH when the tub is filled.

    Be cautious if increasing your KH first, as you will have a hard time adjusting your pH - the water will have a large buffering capacity. I adjust and buffer my pH first (using Seachem Acid and Alkaline Buffers) and then adjust my GH with Seachem Replenish. That way, there is only a very slight increase in my pH (from 7.2 to 7.3) after adding the Replenish.
    Last edited by gronlaura; 05-22-2013 at 11:13 PM.
    75 gal - Smudge Spot Cories, Silvertip & Pristella Tetras, Scissortail & Red Tail Rasboras, Pearl Gourami, Black Kuhli Loaches, Whiptail Cats, Wild Caught BNP
    Dual 29 gals - Diamond Tetras. Harlequin Rasboras, Bloodfin Tetras
    10 Gal - Mr. Betta's Fishy Paradise

    "Life isn't about waiting for the storm to's about learning to dance in the rain"

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts