R/o Water Question!

Puck44

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Alright, so my 20 gallon is finally cycled! The ph is around 7.8-8.0 and we would like to get it to around 6.8, something like that. We are going to keep tetras and Cory’s and fish like that(20 gallon long btw) do if we did 50/50 R/O and tap water how would we make sure that we don’t do to much of one, and make it the R/O water and tap water even? Also what would we have to monitor our ammonia closely after doing a 50 percent water change and outing in the R/O water? Thanks!

So do you guys know how?
 

WTFish?

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I believe your ph is fine for both of those...is there a reason you want to lower it? Just curious because a steady ph is way more important.
 
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Puck44

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WTFish? said:
I believe your ph is fine for both of those...is there a reason you want to lower it? Just curious because a steady ph is way more important.
I wan to lower it cause I know that it is bette for the fish that I want, I will work hard to keep it stable, I am
Just curious how to make it 50/50.
Thanks!

So do you guys know how to do it?
 

Hunter1

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If you have access to R/O water, you’ll have to experiment to get the right PH. Start with a 50% WC with R/O and test.

But I agree a steady PH is better than the correct native PH.

Once you figure out say, 50% WC with 50% tap and 50% R/O (or 60/40 or whatever gets you where you want to be) you should be pretty steady but you may have to also figure out a formula for adding minerals depending on you GH and KH since the R/O removes them.
 

-Mak-

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What you'll want is a GH/KH test kit. RO water has 0 GH and 0 KH. Your tap water should have more. If you do 50% RO and 50% tap, the new KH and GH should be about halfway between 0 and the tap measurement for both.

For example, if your tap has a GH of 8 and a KH of 10, after cutting it with 50% RO it should be around GH 4 and KH 5. The lower KH is what will decrease the ph. Using your test kit you can adjust the amount of RO you're adding
 

Fahn

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Honestly unless you're trying to keep wild caught fish or sensitive Taiwan bee shrimp you should just leave your pH alone. I keep corys and have kept tetras at 7.6 with no issues whatsoever.
 
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Puck44

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Thanks for all the replies! Very helpful!
Say I were to do 50/50 how would I make it exactly the same amount? Also say a few more drops of one went in, would it make a difference?
 

Hunter1

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Puck44 said:
Thanks for all the replies! Very helpful!
Say I were to do 50/50 how would I make it exactly the same amount? Also say a few more drops of one went in, would it make a difference?
No.

If one source is 7.0 and the other source is 8.2, in a 10 gallon water change you would be about 7.6 in theory, then factor that into the existing water, about 7-8 gallons, you would have to be off by gallons to make a significant difference.

But I would introduce the R/O water gradually so you lower your PH gradually.

Maybe start with 80% tap/20% R/O during a 50% WC and test the next day to see how much you went down. Gradually increase R/O percentage.

But like many have said , fish will acclimate to different PH just not PH swings.
 

WTFish?

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Is there a reason you want all this extra work for fish that are just fine in your pH? I’m just really curious. But above advice is great if you really wanted to.
 
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Puck44

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WTFish? said:
Is there a reason you want all this extra work for fish that are just fine in your pH? I’m just really curious. But above advice is great if you really wanted to.
It is a tank with no fish yet and I want them to have the best environment.

Hunter1 said:
No.

If one source is 7.0 and the other source is 8.2, in a 10 gallon water change you would be about 7.6 in theory, then factor that into the existing water, about 7-8 gallons, you would have to be off by gallons to make a significant difference.

But I would introduce the R/O water gradually so you lower your PH gradually.

Maybe start with 80% tap/20% R/O during a 50% WC and test the next day to see how much you went down. Gradually increase R/O percentage.

But like many have said , fish will acclimate to different PH just not PH swings.
Thanks! That’s helpful!
 

Hunter1

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Puck44 said:
It is a tank with no fish yet and I want them to have the best environment.



Thanks! That’s helpful!
If you know where you are getting your fish, I would find out the PH of their tanks. I would match that, or drip acclimate.
 

AquaticJ

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I mean regular RO systems shouldn’t do anything to your PH. A lot of RO systems come with a deionizing filter, which removes nearly all of your minerals (supposed to be for people who don’t want the taste of minerals in their drinking water). Deionized water doesn’t have a PH, in theory. So just start messing around with mixing the water in a bucket, be sure to have acceptable GH/KH levels, which someone already mentioned, because those are what controls your PH. As others have also mentioned, as long as you’re stable, those fish really shouldn’t have a problem. I had to do this for Discus though. Discus are, for a lack of better words, ridiculous.
 

Siggi

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Hi all.
In theory RO/DI water has pH=7. If you want to lower it WITHOUT CHEMICAL SHORT-TERM SOLUTIONS the acidity stabilization should ideally come from the substrate/hardscape. If you have limestone in your substrate, you'll never get your pH down! To get your pH to the acid side of 7, you should take care to have an inert or acid (quartz, granite or in-store bought substrate) substrate. Adding hardwood or oakleaves to your tank will be good.

But I echo previous post in that a stable pH is much more important than trying to reach a certain value and have fluctuationd while trying.

Good luck.
 

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Find out what pH they are coming directly from and try to match that if you want. Then over the next few weeks with small water changes bring them to your tap pH. Messing with it long term isn't something you're going to want to do, its a TON of work. As everyone else has said unless they are a particularly sensitive species your water is fine.
 
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