Water Change Station Sizing Question

[Fish Fan]

Hi all! I'm posting this in the DIY section because ultimately this will be a DIY project. I have been out of saltwater since 2018, but planning a new reef-tank build, and I am trying to design a water change station with fresh and saltwater reservoirs. Back in 2018 I purchased two Brute 45 gallon barrels, and I hope to use them now. I am still finalizing my ideas for a display tank, but I can be certain it will be between 40-65 gallons max, plus two 10 gallon QT/Observation tanks (one fish, one corals). My question is basically: For my sized tanks, I think it's a good idea to have enough reserve saltwater heated and ready to go to do a nearly 100% water change in the event of catastrophic emergencies in any of the tanks, and I think the 45 gallon Brute fits that bill nicely for me. Really what I'm wondering is how much fresh RODI water do I need on hand? It seems a little excessive to keep 40 or so gallons of RODI water on hand. I couldn't use it fast enough, and even with a top on the Brute barrel I would think it would reacted with who knows what in the air, and quickly become at least slightly polluted.

OK, my REAL question is: How do you size your freshwater reservoir? How much fresh RODI do you keep on hand?

Further, for the space limitations I have to work with, my dual Brute water change station will have to be one Brute stacked on top of the other Brute, not side-by-side. I am now thinking of going with a 45 gallon Brute on the bottom, and a smaller, maybe 20 gallon container on top for RODI water.

I should mention I have a BRS 75gpd RODI system, plus their extra 75gpd "water saver" add on, as well as 4 DI canisters. So I can make RODI water fairly quickly, especially given my relatively small tank sizes.

Any thoughts, suggestions, or critiques would be very much appreciated!

Thank you in advance!

 

[Red_Beard]

45 sounds about right to me for that size display. I am running a 75 dispay and a 40b frag, i have 2 55gallon drums for mine. I like to keep the lids on and make whole drums at a time. I have a float valve on the RO drum and will let it fill during the day Saturday and shut it off at the valve when its full. That lasts me about 3 weeks or so for top off. Then i only worry about making water once or twice a month. I have not seen any appreciable difference in tds between day 0 and day 21 with the lid on if that helps.

 

[Fish Fan]

45 sounds about right to me for that size display. I am running a 75 dispay and a 40b frag, i have 2 55gallon drums for mine. I like to keep the lids on and make whole drums at a time. I have a float valve on the RO drum and will let it fill during the day Saturday and shut it off at the valve when its full. That lasts me about 3 weeks or so for top off. Then i only worry about making water once or twice a month. I have not seen any appreciable difference in tds between day 0 and day 21 with the lid on if that helps.

Thank you for your reply! Great to hear your RODI water doesn't pick up and lot of contaminants, that was a big concern for me.

 

[Indymann99]

I am space limited so I just use a Mix tank (brute) and RODI is plumbed to 1. a 5gal ATO reservoir next to sump 2. the Mix tank to fill and 3. to the the QT tank for manual ATO. When I do WC, I immediately refill the Mix tank with RODI and mix in salt. My mix tank has pump that runs 20min every 4hrs, also has heater, so water is always ready to use. I typically do WC every 30days. I plumbed the mix tank to the sump so I can pump fresh salt water to the sump (no buckets or hoses). I have to fill the 5g ATO every week.

 

[Fish Fan]

I am space limited so I just use a Mix tank (brute) and RODI is plumbed to 1. a 5gal ATO reservoir next to sump 2. the Mix tank to fill and 3. to the the QT tank for manual ATO. When I do WC, I immediately refill the Mix tank with RODI and mix in salt. My mix tank has pump that runs 20min every 4hrs, also has heater, so water is always ready to use. I typically do WC every 30days. I plumbed the mix tank to the sump so I can pump fresh salt water to the sump (no buckets or hoses). I have to fill the 5g ATO every week.

That’s a great setup! And it seems to me that not having a large volume of fresh water hanging around isn’t really a problem for you? My space is limited as well, so if I use two Brutes I’m going to have to stack them. I think life may be easier if I only need the one Brute.