City Well Water / RO questions

BigSteely

Junior Poster
Nov 25, 2016
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Turlock, CA
i have some confusion from trying to read too much....


I plan on using the EI method.....


should i use well water or RO water for my weekly water change?


tap water is around 5-6 KH. I live in the central valley of California... water is on the hard side.


i do have a RO/DI from my salt water days.


should i plan on just using RO water?


Thanks....
 

Pikez

Rotala Killer!
Moderator
May 12, 2013
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Close (but not too close) to LA
I live near LA/Ventura county and we use some of the same water you have. I have used both tap water and RO. I can grow most plants really well in hard, alkaline tap water.


I say go with just tap water. And use the time/effort saved for maintenance, water changes, cleaning, and optimizing CO2.
 

thelordofthefish

Subscriber
Apr 22, 2017
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I will double down on this: I live in LA and I'd prefer to go with RO water...but if I do, what do I need to know in terms of re-mineralizing the water? I can't seem to find a good tutorial so to speak.
 

ilikeasianbooty

New Member
Aug 4, 2017
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Fairfield,Ca
I believe most people only use RO/DI for reef, shrimp or to preserve the buffering effects of certain soil to my knowledge, but dont quote me on this im a total noobie :)
 

Christophe

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Oct 3, 2013
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Albuquerque, NM, USA
I will double down on this: I live in LA and I'd prefer to go with RO water...but if I do, what do I need to know in terms of re-mineralizing the water? I can't seem to find a good tutorial so to speak.

If you really want to work from RO, you basically want to add back in a couple different things:
  • GH components -- primarily Calcium and Magnesium, both used by plants directly. How much of each? Kinda depends on your goals, what plants or animals you want to keep. You will be successful with a WIDE variety of the things we typically keep in a planted tank with GH 3-5 degrees. You might see some online discussion of Ca:Mg ratio, but overall there doesn't seem to be evidence to suggest it's terribly critical. You just need to have both present. Shoot for a 3:1 ratio of Ca:Mg, adding enough to get you to 3-5 dGH and call it good.
  • KH components -- carbonate and/or bicarbonate, for buffering pH. Again, how much you need depends somewhat on what plants and animals you're keeping. Most common soft water fish & plants will do well in the 2-4 KH range.
Probably the most important consideration in re-mineralizing is to be consistent. Don't radically change your composition from one week to the next -- if you want to change composition, work your changes in gradually over several water changes.

Take a good careful look through the Articles section https://barrreport.com/articles/ of this site. Tom Barr has a LOT of good information about many of the various elements you might want to control in re-mineralizing your RO.

Compounds that you can use for this:
  • CaSO4 -- good primary calcium source. The sulfate is useful to plants also to some extent. Look for food grade CaSO4 at brewing supply shops. Some people might suggest plaster of paris, but that has other stuff in it that you perhaps don't want, in quantities that aren't really specified well.
  • CaCl2 -- can use a bit of this too, but don't overdo the chloride. Plants use some chloride, but too much can be associated with problems. How much? Dunno, it's a matter for debate. I'm keeping mine under 10ppm just to be safe & sensible. This is another one to get from the brewing supply shop.
  • Ca(NO3)2 -- If you want to incorporate some macro dosing into your water change. Aquarium fert shops online might have it.
  • MgSO4, or Epsom salt -- good primary magnesium source, super-cheap at your local drug store. Four years ago, I bought three pounds for $2. Still got half of it!
  • GH Booster -- a mix of CaSO4, MgSO4, and K2SO4, from aquarium fert shops. All of what you need plus potassium, never a bad thing.
  • Seachem Equilibrium -- Ca, Mg, and K, plus a good slug of iron and Manganese as well. Aquarium shops generally have it.
  • Potassium Bicarbonate -- best bang for the buck KH supplement, plus a potassium boost! Find the food grade stuff at the brewing supply shop.
  • Sodium Bicarbonate -- aka baking soda. Dirt cheap and common, but also adds sodium which is not terribly useful for most plants. Sodium is another thing to perhaps keep to a low level since you're mixing water from scratch.