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Hard Water vs. RO for South American Fish

Discussion about fish health and water chemistry.

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Schgar Level 1 Member
Level 1 Member

Posts: 19
Location: Rogers
Hi All,

I am a fan of Angels, Discus, Rams, and planted tanks. My ph out of tap is 8.5, I assume all of MN is this way? I would like my fish to thrive, not just survive, I may want to toy with breeding.....had success in another state prior to moving to MN.

I want to go RO I think, I am not a plumber nor a chemist. Even though I have kept fish for years, I am a novice when it comes to water chemistry.

I am looking for any and all suggestions....do I buy a RO Buddy? Do I call Culligan? Do I begin to use chemicals and mess with the Ph? As always, money is a limited resource, but it is my hobby.

Open to any and all suggestions. Remember, I am not a chemist nor a plumber.
Thank you in advance.

Passionfish Level 20 Member
Level 20 Member

Posts: 12064
Location: apple valley, mn
In Twin Cities there is tapwater from aquifers and rivers. Your tap water is from aquifer, hence pH greater than 8. All species in question will survive at this pH, howevare very few will breed at this pH. To lower pH to less than 7 will require RO water. Using acidic chemicals to break carbonate buffer is possible but not advised. RO membranes last longer when tap water general hardness is low or zero. Using house water softener is good feed water to RO system and is good for washing clothes and bathing. Straight tapwater can be used with RO system but RO membrane will need to be replaced frequently.
It is not necessary to pull permit and higher plumber to install RO unit. If you are not comfortable tapping into water lines, find someone that is. A drain or storage tank for waste water will be needed. A storage container for RO water is needed. If a tank is set up for continuous water change then may not need storage.
Depending upon post RO membrane filter in RO system, it may be necessary to lower pH further. I add sphagnum to filter or place it directly in tank.
Like a complete unknown

Schgar Level 1 Member
Level 1 Member

Posts: 19
Location: Rogers
Thanks Passionfish, I assume you have the RO system? Do most people on this forum have an RO system? I am just looking into it, lots of Youtube videos to learn as well. Do you have a specific recommendation?

Passionfish Level 20 Member
Level 20 Member

Posts: 12064
Location: apple valley, mn
Likely all salt water tanks start with RO water to control ionic content. Never set up salt water though. Fresh water keepers with tap water sourced from surface water may not need RO unit. However, there are those with surface water that use RO units. Not sure how many of us with hard tap water are using RO systems.
IMO there is a reason for not using RO. It is much easier just easier to keep fish that do well in hard alkaline water or fish that do well in whatever tap water chemistry exists.

If one is willing to take on extra work and costs then we acquire an RO system and get to it. I have purchased RO items from airwaterice.com. Prices are good. Advice and service excellent.
Like a complete unknown


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