Results 1 to 5 of 5

Thread: RO/DI newbie

  1. #1
    Curious Reefer
    Join Date
    Dec 2009
    Thanked 0 Times in 0 Posts

    RO/DI newbie

    Hi guys,

    New to sw tanks and all of this jazz. Trying to take in all that I can and loving the podcasts.

    So I live in an area that has a high arsenic level in the water. The city does filter and most homes have ro/di systems installed at construction. However mine does not. So im looking at getting a system.

    My question is this. So these RO/DI filters are rated at gallons per day (GPD) but in the podcast about RO/DI he says a 100gpd filter produces about 20 gallons per day actual water. How exactly do you guys fill up large tanks like that? Ive gotten a 55g tank, and am thinking that its going to take about 3 days to fill it? im thinking the best method would be to get a 55g trashcan and fill that before I fill my tank for the first time, after that water changes wont be a big deal but the initial fill seems like a pain.

    One more question. after my initial fill, if I fill the trash can again and have it available for water changes, how long will the ro/di water sit? should I mix the salt water into the 55g trash can for my first fill or do it in smaller doses? Can I mix the salt water in the 55g trashcan and store it?

    Thanks guys

  2. #2
    Grand Master Reefer CarmieJo's Avatar
    Join Date
    Jan 2006
    Raleigh, NC
    Blog Entries
    Thanked 179 Times in 166 Posts
    Hi chbix and to TR!

    Lots of us use Brute trash cans for storing fresh and salt water. I keep SW in a 35 gallon one for weeks at a time. I store FW in 5 gallon jugs.

    Once you add sand and rock to your tank it will not take 55 gallons of water to fill it up. I don't see any reason why you could not mix all of the water at once. In fact, for the initial fill you can mix the salt in the tank. Do not put your live rock in to start. Put your sand (dry sand is fine, you don't need to buy the live sand in a bag) down in the tank, cover it with a plastic bag set a plate on the bag and gently pour the water onto the plate. Once you have the tank about 2/3 of the way full (keep track of how much water you use) pull out the bag, add the salt and let it mix over night. You can check the salinity after an hour or so and adjust from there. The next day you can add the rock.

    At the same time have some more water mixing up in your Brute or whatever. I like to always mix my water overnight. After you add the rock use this water to fill the tank the rest of the way up.

    The bag and plate trick will help prevent a sand storm.

    Only disasters happen fast!

    Carmie's 54 Corner Tank
    Carmie's Cube

    Show people you value their advice! Click the STAR icon at the bottom of the post to add to their reputation.

  3. #3
    Grand Master Reefer rroselavy's Avatar
    Join Date
    May 2006
    Los Angeles
    Thanked 2 Times in 2 Posts
    I have a 44g Brute (with a Kent float valve) in an outdoor shed for RODI. The shed has an empty laundry closet (complete with water supply and drain) that we were not using, which was a perfect place for me to stow the RODI unit, the 44g brute for RODI, and a smaller 24g Brute for SW.

    My "100gpd" RODI takes about 27 hours to fill up the 44g container, so I would estimate I get about 40gpd. Throughput all depends on your incoming water pressure and your rejection rate. Some people will use a pump to increase the input pressure.

    I originally mixed my SW in the 44g brute, which was nearly enough for my 56g tank w. sand and LR.

  4. #4
    Expert Reefer meoklmrk91's Avatar
    Join Date
    May 2009
    Thanked 0 Times in 0 Posts
    When I first filled my 30G tank i did it all in 9L buckets. I let the RO/DI fill a bucket, mix the salt in and then put it in the tank, it took me a long while but I was just so excited to get the tank filled I was willing to use any means necessary. Now I have 2 60L tubs which I fill and then mix. You are going to want to buy some large tubs or bins you then can just walk away and let it fill then mix and put it in your tank. This will probably be the only time that you will have to do this[unless you get a bigger tank], water changes are very minor usually at the most 30%.

    If your planning on storing it then your going to want a container that you can keep covered to make sure that the water doesn't get contaminated. If find that it's best to keep two containers, one for SW and one for RO/DI water with some in each at anytime. Its comes in handy in an emergency and also you will need some RO/DI for top offs between water changes.

  5. #5
    Insightful Reefer AZDesertRat's Avatar
    Join Date
    Jun 2009
    Phoenix AZ
    Thanked 12 Times in 11 Posts
    I have not seen the podcast but RO GPD is dependent on two main factors, water pressure and water temperature. 20 GPD out of a 100GPD system is not realistic, the norm is probably more like 2/3 to 3/4 of the rated GPD for most users. A 75 GPD Dow Filmtec RO membrane, which is the most popular by far, is rated at 75 GPD at 50 psi pressure and 77 degrees F water temperature. Other things have a lesser effect like tap water TDS and waste ratio but psi and temp are the main two. You can find a real nice calculator here which gives you an idea of how pressure and temperature affect GPD:

    If your water pressure or temperature are lower the output will be less and vice versa if they are higher it will produce more. Pressure and temperature can both be overcome with a booster pump installed with the RO or RO/DI unit but this is not normally needed.

    Many of us use trashcans like the Rubbermaid Brute, I use a 23 gallon rectangular Rubbermaid recycling can myself as it fits perfrctly in the space I had available. It controls the starting and stopping of my RO/DI system via a solenoid valve and float switches, when the level in the can drops about 10 gallons the RO/DI starts and refills the can until it hits the top float switch shutting it off.

    The aquarium is fed via an autotopoff system from the 23 gallon storage can so I always have RO/DI available for topoff andwater changes. The water stays good for months no problem as long as it is somewhat protected from the elements, ie extreme heat or cold, dust and direct lighting. It stays covered so I keep everything out and its in my climate controlled garage.

    If you are in the market for a new RO or RO/DI system pay attention to the system you buy as there are many different quality levels and what may appear to be too good to be true usually is. Expect to pay a minimum of $150 for a true reef quality RO/DI and upwards or $300 for an exceptional system. You really need to have an idea of your water conditions before buying to make sure you get a system that will handle your needs, they are not one size fits all if you want a good system. If you can supply the vendor with info on your tap water TDS, pressure and temperature that is a good start.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Powerheads,Hydrometer, Testers, Buffers, Salt and RO/DI
    By meoklmrk91 in forum New to Saltwater
    Replies: 3
    Last Post: 05-23-2009, 01:30 PM
  2. RO/DI Unit - running line
    By Kassun in forum General Marine Discussions
    Replies: 8
    Last Post: 04-24-2008, 11:25 PM
  3. Removal of Cannister Filter, Boi-Balls & Future Use of RO/DI Water
    By Dean Murphy in forum Marine Tank Problems
    Replies: 3
    Last Post: 07-26-2007, 10:51 PM
  4. RO/DI testing
    By bubbletip in forum DIY Projects
    Replies: 12
    Last Post: 09-18-2006, 06:20 PM
  5. Whered you get your Ro/Di filter??
    By Small Fry in forum Discussion Lounge
    Replies: 8
    Last Post: 08-21-2006, 09:33 PM


Posting Permissions

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