Trying to use RO/DI water in my tanks

Discussion in 'Aquarium Water' started by Beausoleiljacob, Jul 29, 2015.

  1. BeausoleiljacobValued MemberMember

    Hi Fishlore,
    I have a few problems on hand at the moment and not sure what to do.
    Im trying to use this RO/DI water for all 3 of my tanks. My goldfish, my angelfish and my livebearers/Neons. I added all the needed additives according to the directions. I added 1 tsp of Alkaline Buffer because my pH was so low 6.5 after DI, 6 caps of replenish to get my GH to 6 and 1 cap of Fresh Trace. Anyways, right now my parameters of the RO/DI water is pH-7.8 gH-6 and kH-2.5. I have more than 20 gallons of water in my brute container so I have no idea why it sent my pH skyrocketing! Please help! I have no idea what to do and have to do water changes tonight because I am leaving for vacation tomorrow!
    Thank You!:)
  2. CindiLFishlore LegendMember

    Alkaline Buffer will put your ph between 7.8 and 8.2 so its actually on target. A ph like this will be fine for your goldfish and your livebearers. As far as the angelfish goes, all fish adjust to ph as long as its stable. How long ago did you add in the alkaline buffer? How long are you leaving for vacation?

    I would leave everything as is. GH of 6 sounds good :)
    1 cap of fresh trace is good :)
    Ph of 7.8 is actually good too as long as it is stable. Your KH is borderline still.....thats why I ask how long you'll be gone? I would almost say to add in another 1/2 tsp but you could wait a number of hours, test it all again and then decide. Sometimes it takes a number of hours to "settle". After that you could re-test the KH.

    I should be around all night if you have more questions.

  3. BeausoleiljacobValued MemberMember

    It has only been in there an hour or 2 and I only added enough for 20 gallons and have 28 gallons of water in there. Should I add more. I just don't want the pH to go much higher! Will my fish be okay with change. How much of a change would you recommend again? Im only leaving for 3 days! And I'm so thankful for all the info! You know your stuff!

  4. CindiLFishlore LegendMember

    How much of the water did you replace with the RO in the tanks?
    How do they seem? They have a much easier time going up in ph then sudden drops in ph. Lots of people buffer their water and I've never heard of it hurting them. Seems like the directions say a tsp per 20g like you mentioned, wait a day and then add more if need be. I'd wait a few hours and test it all again.

    You must not have realized alkaline buffer puts ph between 7.8 and 8.2? If it makes you feel better, my RO water starts at 6.0, rises by itself (without the buffer) to 8.0 but has almost no KH. I use about a tsp of it also on my 33g tank and it still settles around 8.0. So what I'm trying to say is you shouldn't see a giant rise or anything from where its at. If you look at the back of the bottle it should say how to mix in acid buffer to achieve the ph you desire. I don't do this only because my natural ph is actually around 8.0.

    I would aim for a KH of around 4 and up.

  5. BeausoleiljacobValued MemberMember

    I haven't added it to the tanks yet. I will as soon as I get your okay! I just added another 1/2 tsp to the container and my kH before I added it was at 3 so lets hope that helps. How much of a % would you reccomend for 2 10 gallons and a 29. I just test both the pH and kH again. the pH was at 7.8 still and kH at 3 was like green and at 4 was bright yellow. Should I add more?
    Last edited: Jul 29, 2015
  6. CindiLFishlore LegendMember

    So you're just switching to RO now right? Your tanks are all tap water currently? What is the ph, gh and kh in your tanks right now? Also, do you have the water in the brute tank heated to match your tanks or within a couple of degrees?
  7. BeausoleiljacobValued MemberMember

    Correct! I have been hauling jugs of water from my work since they have city water. My tap water since we have a well has a TDS of 600 and a kH of 16 and GH of 0. I tried keeping a betta once in this water and it died within a week. Poor thing. I never trusted it every since. The water inside the brute container is at the correct temps.

    The levels of my other tanks are as followed:

    Livebearers & Neons:


    Despite all my screwed up levels of gH and kH all my fish seem to be thriving and showing no sign of stress. The tap water my fish are using has a kH of 3 and gH of 2. I dont know what my tanks are doing i'm just glad everyone has been okay! Whatever you say is what I'm doing because I have no clue what to do
  8. CindiLFishlore LegendMember

    Oh, ok, I get it now. Not sure if thats why your betta died though....just saying....your water sounds a lot like mine except I also have high nitrates which is why I switched to RO.
    Wow, I feel so responsible, hope everything turns out ok! :)

    So you have a total of 20gallons RO?
    You have two 29g tanks and the 10g right?
    I think I would add the water the way you have it and then after an hour test them all and see which if any need more adjustment (more buffer or replenish).
    Seems like you have enough to do a 30% change on both your 29g tanks for approximately 8.5g each and then a 30% also on the 10g. Just remember RO is just water, but void of nutrients.

    After the 30% changes, wait an hour with your filters running, test your water and lets see where you're at. After that you can fine tune them a little since they are starting off a bit different from each other. The goldfish and angel fish tank PH's have dropped due to low KH. You will probably need to add more replenish for sure to the goldfish and livebearer tank and probably a little more buffer but lets see what the exact numbers are first ok?

    Sorry for rambling, hope that all makes sense.
  9. BeausoleiljacobValued MemberMember

    I have 2 ten gallons and 1 29. I have 1 fancy goldfish that will be rehomed into my not setup yet 55 gallon. And I have the angel fish in the 29 with neon tetras she is very nice to them and doesnt pick on them. and the platys in the other 10. Not exactly. I have about 30 gallons of water total I think. I have a 32 gallon brute with maybe 3 inches to the top. So probably less than that. After adding 6 caps of replenish and 1 & 3/4 of the buffer I have hit a gH of 6 and kH of 4. the pH is still 7.8. I will ad another half cap of Fresh Trace because I didn't add enough. I will get going on those water changes. It might be a while heaven now how long this is going to take considering it is my first time using my pump. LOL I'm sure you will do great! with all you info!
  10. CindiLFishlore LegendMember

    Good luck, sounds good! I was looking at your profile for the tank information. I use a pump too. Once you get used to it, its awesome! I'll check back periodically.
  11. BeausoleiljacobValued MemberMember

    Hi again!
    I just finished up! I was only able to finish the 29 gallon for full. On the 2 10 gallon I maybe took out 2 gallons of water. The problem was I though the adapter I got for my pump would fit because the tubing I got was 3/4 inch but I guess not. Should I test the water in an hour? Thanks for all the help! What should I do try to get everything to the same? Or to the perfect levels for the fish? Also, how do you go about using your pump? How do you shut the water off from going into the tank I still don't quite understand that aspect. Would you be able to give me a proceudre?
  12. CindiLFishlore LegendMember

    Yeah, test the water in an hour and lets see what they are. I'd say aim for at least KH of 5 or higher, GH of 7-9. You already added fresh trace so I think that should be about perfect :)

    I don't know what system you have so I don't think I'll be much help there. I use a small pond pump with an adapter that I fit a 1/2" garden hose to, to pump my water up from a bin to the tanks. My RO comes from my kitchen faucet so its probably a different system.

    Edit- Also, you're welcome. Its a pain in the butt figuring out all this stuff and I've had over 3 years of bad water and finding different solutions around it.
  13. BeausoleiljacobValued MemberMember

    I'm going to test the water in about 15 minutes. Everyone seems to be acting perfectly normal! So that good!

    Okay. So I tested the Live Bearers Tank and there is a little of a problem. The pH now is 8.0-8.2 so 8.1, kH-4? I'm not sure at 3 drops it turned green and that finally at 4 drops turned yellow. gH-5 (It went down from the initial RO/DI water.
    Last edited by a moderator: Jul 30, 2015
  14. CindiLFishlore LegendMember

    Honestly I wouldn't worry about the ph. Ph is fine at 8.1 and KH of 4 should be ok too. I would add more relenish and get it up to 7 or 8.
  15. BeausoleiljacobValued MemberMember

    Okay! Can you explain why the pH doesn't really matter and why the gH does mater?
  16. CindiLFishlore LegendMember

    A ph of 8.1 is perfectly fine as long as its stable. It should be stable at a KH of 4 but I would test again in a few days when you get back. If that bothers you, you can buy the Seachem Acid buffer and follow their ratio to bring it down to 7.5 but I personally think its fine. At least my goldies and livebearers and everyone else have always been fine in a ph of 8.3 and now 8.0 with my RO water.

    Gh: Some of your fish are "hard water" fish meaning they need more minerals in their water for osmotic functioning and health. GH is mostly calcium and magnesium. In general, soft water fish will get what they need from water thats harder but hard water fish like goldies and livebearers cannot get what they need from water that is too low in GH so having a higher GH helps their health.
  17. BeausoleiljacobValued MemberMember

    My only concern with the acid buffer is it brings down my kH! What should I do then?
  18. CindiLFishlore LegendMember

    Oh, acid buffer won't bring your KH down, just your ph. There should be some ratios on the back of the bottle I think.
  19. BeausoleiljacobValued MemberMember

    What exactly does kH do?
  20. CindiLFishlore LegendMember

    KH basically stabilizes your PH. Here is a link that you might find helpful:


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