Switching To R/o Water

Discussion in 'Reverse Osmosis Filter for Freshwater' started by stella1979, Apr 18, 2017.

  1. stella1979ModeratorModerator Member

    My tap water has fluctuating levels of nitrates, lately as high as 40ppm so I am making the switch to R/O. We already have a 5 stage system installed, but have not used it in the tanks yet. I know I need to remineralize and buffer the R/O water. After stalking the posts of some more experienced aquarists, namely @CindiL, I decided to go with these products... Replenish, Fresh Trace & Alkaline Buffer.

    I know these products will come with dosing instructions, but I'm nervous. I plan on doing some testing in buckets this weekend. So, after I dose these products, how long to wait until I can get accurate test results? Any pointers from you more experienced folks on dosing with these products?

    Once I've got my mix right, I'd like to know the best way to introduce the new water to the tanks. Will I just introduce it with my weekly 30% WC's? If I can get the levels where I want them I'll only be lowering pH from 8.0 to 7.8. GH in my tap is pretty high at 18 and tap KH is 11. I'm not quite sure what hardness levels I will achieve with the Seachem products but imagine that I will be able to control that by correctly dosing the Replenish, yes?

    I'm sorry folks, I'm trying to learn this stuff but chemistry was never my strong point, actually avoided it like the plague while in school :rolleyes:
  2. CindiLFishlore LegendMember

    Hey Stella, so initially I would just mix in straight R/O for water changes to slowly bring your levels down to where you want them. (Is this for your fantail tank, the guppies or both? ) Once you have them where you want them then you'll just treat the new water for water changes with replenish and buffer and trace. Are you using buckets or a python?

    I'd aim for a KH of 6-7 and a GH of 8 or so, for the guppies I'd aim for a GH of 10-12, they need hard water. For new water, you'll get used to the dosing since it will be the same with every single water change and you won't have to think about it much.

    Dosing: 1 tsp alkaline buffer per 20g water brings KH up by about 3 degrees. If your RO is 0 dKh and you change out 6 gallons a week then you'd use about 1/2 tsp buffer approximately.
    One capful of replenish per 20g does the same, brings it up by about 3 degrees so if you're aiming for a dGh of 8 and you change out 6g a week you would want roughly a capful a week per 6g. For the guppies, you'll want to use more than this, I'd say a cap and a half full for 6g. Double check to see what it takes to get it to 10-12.
    You'll obviously need to play with it but thats where I would start.
    Thats pretty close to what I follow myself. I change out 12g a week in my 33g and use 1- 1 1/4 tsp buffer and 2 capfuls replenish.

    Trace I just use a capful with every water change.

    By the way, I avoided science myself in school and my only chemistry education has been with my fish hobby lol. I guess the best way to learn something is hands on right?:p
    Last edited: Apr 18, 2017
  3. stella1979ModeratorModerator Member

    Thank you once again Cindi:joyful: I am using buckets, just got one with measurements on it just for this. I think I'll only be mixing up 3 gallons, (guess I should have gotten more buckets:)),at a time but it'll be easy enough to halve the measurements you gave me. Hands on experience will surely make me more confident but I'm not worried about measuring. I'm also a baker, so I've got lots of measuring tools and a couple of good scales if it comes down to it. So, the remaining question is, how long do I wait to test after dosing? I guess it's pretty quick, right?
  4. CindiLFishlore LegendMember

    Yes, just long enough for it to be mixed into the tank. As far as testing the bucket, an airstone for 5 minutes or just stirring it around until the buffer dissolves (which is quick) is all it will take. The replenish looks like dissolved salt when it goes in (if you've ever seen that) but mixed in very quickly.
    Make sure to shake the replenish each time you use it as the mineral fragments/tiny pieces tend to settle on the bottom of the bottle.
  5. stella1979ModeratorModerator Member

    OK, so after a busy weekend I finally got around to testing my RO water with the additives. I put 3 gallons RO water in a bucket. I added 3/4 capful of Replenish and 1/4 tsp. alkaline buffer and stirred for a couple minutes. I thought everything was mixed well so I went ahead with testing.

    KH - 7
    GH - 15
    pH - 6.8

    I've now added a small pump to the bucket to mix it around and create surface disturbance. I will test again in an hour. I was expecting the pH to be higher. KH is right where I want it to be so if pH remains low, how will I get it to where I want it to be without also altering the KH? I wasn't expecting to change my tank's pH dramatically. Right now the tank is filled with tap water and pH is at 8. I thought the alkaline buffer would bring the RO's pH to 7.6 or so.
  6. CindiLFishlore LegendMember

    Does your ph always come out of the tap that low and then rise like that? If so, I am thinking it will rise with the airstone in there as it offgasses CO2.
  7. stella1979ModeratorModerator Member

    The pH out of the the tap is 8 and it stays there. When I first tested the RO's pH (without the additives) it was 6.4. But, I read that ph can swing in untreated RO water so I tested the same glass of water 24 hours later and got 7.2. That was a couple of weeks ago before I learned about remineralizing RO water.
  8. CindiLFishlore LegendMember

    Oh yeah, duh ha ha. I knew this was RO water. Have you retested it since earlier today to see where ph is at now?
  9. stella1979ModeratorModerator Member

    pH rose to 7.6 after circulating the water for a couple of hours. I left the circulation on and am planning on using this water for a wc tomorrow. I'll check pH again first, but is there any reason to think it will change from this afternoon? It felt like such a small amount when I only added 1/4 tsp. of the buffer to 3 gallons, lol :)
  10. stella1979ModeratorModerator Member

    OK, so I just tested again and got pH-8, KH-7, GH-15. pH is the same as tap, but I think that's fine. I think I'll go ahead and use this water tomorrow because I want to lower KH and GH gradually anyway. The point of all this was to have nitrate free water anyway. I'll test again first to make sure the pH has remained stable at 8.

    Next mix I am going to try to achieve KH-6 & GH-11. Assuming I dose correctly to those levels, would I expect my pH to change at all?

    On a side note, I just received Kanaplex. Yes, Amazon delivery just knocked on my door at 9:30pm:rolleyes: The box was taped shut and is intact and everything. Upon inspection the container appears more than half empty. Is this normal?
  11. CindiLFishlore LegendMember

    Yes, the container is never all the way full so I think thats normal.

    A KH of anywhere around 6 and up is great, though you will probably want to aerate your water before water changes now seeing how much the ph went up. I am assuming it wouldn't have done that by itself in a bucket overnight but I guess you could figure that out unless you dont' mind aerating it.

    I also have to aerate and heat my RO water overnight because it comes out of my RO tap in the low 6's. Once i add buffer and aerate it rises to 7.9 exactly every time.