Jump to content

Why Lower KH If It Causes Swings In Ph?


tetra
 Share

Recommended Posts

Hello Everyone,

So for a while, I've been questioning why I lower KH if it causes swings in PH. I know you should lower KH to lower PH but doesn't that mean the PH would swing? Its been a very confusing topic for me for a while. 

Thanks in advance.

  • Thanks 1
Link to comment
Share on other sites

When PH is low, Ammonia turns into ammonium and is much less toxic to fish.  How you lower things and how you filter your aquarium, the full setup is important.  Dilution is just as important as what your PH is... If your tank is overstocked, it doesn't mean you should lower PH, but it speaks to how fish are naturally adapted to certain ranges and parameters.

@tolstoy21 or @jwcarlson how do you two handle this in your setups for something like breeding setups and lowering PH?  Is it always low?

Percent abundance of ammonia and ammonium across a range of ...

  • Love 1
Link to comment
Share on other sites

I might not be a great example of this, but I just use my straight tap water for everything that I'm not trying to breed.  My discus are in my GH of 22, KH of 18, pH of 8.2 tap water.  I've successfully kept a ton of fish in this water over the years (discus, oscars, various tetras, corys, etc).  More recently I've had some apistos in the straight tap as well, but that's on the order of months not years, so I cannot comment on longevity or anything.  They've spawned in it and extra males in community tanks seem to be fine in it.  I personally think that hardness and pH are quite overblown for just standard community tank fish keeping.  That's not to say that there are not drawbacks or potential drawbacks.  I'm sure there are.  

The exception to this (for me) would be fish I'm trying to breed.  So my apistos are in mostly straight RO with some tap mixed in a bit.  I have not targeted lowering pH and am just letting the RO be lower pH than my standard water is.  For me, this seems to settle somewhere in the mid-7s.  7.4-7.6 pH.  I have purchased a "nice" pH meter assuming that at some point I will have to artificially lower the pH and to do that I'm going to have to add something.  Be it muriatic acid or peat or something like that.  I struggle so much with the liquid tests, I decided to invest in something that I *think* I can trust.  Especially if I'm going to start dropping down into the 5s.  I don't have ANY experience below about 7.4 or so.  So I'm nervous because I haven't been there...

In any event, the other exception would be wild caught fish.  I don't think it's reasonable to expect a wild caught fish to get tossed into tap water and thrive (unless your tap water is close to what they're in naturally).  

Edited by jwcarlson
  • Thanks 1
Link to comment
Share on other sites

@nabokovfan87 Once you’re down around a Ph of 4 there are no swings. It kind of bottoms out. I have no KH in the water and use peat to keep it as low as possible. My well water has a KH somewhere between 0 and 0.5. The ph hangs at about 6.2 to 6.6. Most of the fish I keep can handle a much lower Ph, so I don’t overly worry about them. Only once did I experience a crash and that was in my crystal red tank. It sunk to about 5 and I started to have a massive die off.

  • Thanks 1
Link to comment
Share on other sites

Here is a fine introductory article on this subject, explaining KH and GH as they pertain to aquaculture.

Low carbonate hardness (KH) will make pH susceptible to rapid crashes. Water changes help to rebalance soft water. I'm in that situation. my pH comes out of my tap at 7.8, but in some aquariums, it crashes to 6.0 pH very rapidly. All of this can have an impact on biological filtration.

GH typically reflects a measurement of calcium and magnesium dissolved in water. Some species of fish require low GH to trigger spawning (e.g. rainwater). Others need a high GH to stay healthy. 

  • Like 2
  • Love 1
Link to comment
Share on other sites

On 4/29/2023 at 9:53 PM, jwcarlson said:

Be it muriatic acid or peat or something like that. 

I find that a large Jehmco box filter stuffed with fluval peat pellets bubbling away in RO water will keep the ph between 4.5 and 5,5. This is in a 20 gallon aquarium. If you want to nudge it closer to the lower end of 4, put a bunch of oak or Indian almond leaves in the tank, or use dark water extract. 

On 4/29/2023 at 9:58 PM, Fish Folk said:

Here is a fine introductory article on this subject, explaining KH and GH as they pertain to aquaculture.

Low carbonate hardness (KH) will make pH susceptible to rapid crashes. Water changes help to rebalance soft water. I'm in that situation. my pH comes out of my tap at 7.8, but in some aquariums, it crashes to 6.0 pH very rapidly. All of this can have an impact on biological filtration.

GH typically reflects a measurement of calcium and magnesium dissolved in water. Some species of fish require low GH to trigger spawning (e.g. rainwater). Others need a high GH to stay healthy. 

Yeah pretty much what fish folk said. 

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

On 4/29/2023 at 6:59 PM, tolstoy21 said:
On 4/29/2023 at 6:53 PM, jwcarlson said:

Be it muriatic acid or peat or something like that. 

I find that a large Jehmco box filter stuffed with fluval peat pellets bubbling away in RO water will keep the ph between 4.5 and 5,5. This is in a 20 gallon aquarium. If you want to nudge it closer to the lower end of 4, put a bunch of oak or Indian almond leaves in the tank, or use dark water extract. 

A lot of people use bags of soil too to buffer things down at or below 7.  Normal ranges are 6.5-7.

My water comes out of the tap in that range, adding the soil doesn't buffer it down much, but I also don't have nearly enough to do that.  It's common practice in caridina shrimp keeping to have those very low PH ranges (5.5) and to just use a ton of soil.  Mesh bags with soil, etc.

Link to comment
Share on other sites

On 4/29/2023 at 8:59 PM, tolstoy21 said:

I find that a large Jehmco box filter stuffed with fluval peat pellets bubbling away in RO water will keep the ph between 4.5 and 5,5. This is in a 20 gallon aquarium. If you want to nudge it closer to the lower end of 4, put a bunch of oak or Indian almond leaves in the tank, or use dark water extract. 

How often is the peat exhausted?  And can you see anything in tanks with this many tannins?  I've got peat, but haven't used it yet.

Also... when you change water are you just changing in straight RO?  Or are you also lowing pH of the WC water?

 

Sorry to veer this off topic.

Edited by jwcarlson
Link to comment
Share on other sites

On 4/29/2023 at 10:10 PM, jwcarlson said:

How often is the peat exhausted?  And can you see anything in tanks with this many tannins?  I've got peat, but haven't used it yet.

The fluval pellets don’t change the water color much at all. The leaves and extract maybe add a yellowish tinge at best. I really don’t keep track of how long the peat lasts, but I probably should. Maybe a couple months?

  • Thanks 1
Link to comment
Share on other sites

My tap water is lower pH, soft, with basically 0 to little KH. I’ve been surprised that with the addition of botanicals to my blackwater aquarium that the values are basically the same as before I tossed a bunch of stuff in the water and turned it as dark as I can. I haven’t witnessed any of the above parameters shift, basically at all. Maybe I already have blackwater conditions out of the tap? Idk. 🤷‍♂️
 

At any rate, it’s been fun to turn one of my tanks into a dark, barren, wood aquarium with a couple epiphyte plants, and my Neo shrimp and Ramshorn snails continue to thrive. Like I said, maybe I already have basically blackwater conditions out of the tap (minus the tannins and tint) but I’ve been able to keep and breed everything I’ve wanted to with the exception of Black Rams. 
 

All this is to say, if your fish get acclimated to your tap water everything should work out. Don’t overthink it, and try to keep it simple! I focus on consistency in environment instead of chasing numbers the internet tells me I need to have. 

Edited by AllFishNoBrakes
  • Thanks 1
Link to comment
Share on other sites

On 4/29/2023 at 7:28 PM, AllFishNoBrakes said:

All this is to say, if your fish get acclimated to your tap water everything should work out.

I've bought Seachem Alkaline Buffer a month ago and I've seen an improvement in my fish. My KH used to be 3 and my rainbowfish would start shimmying a lot, but after I added that Alkaline Buffer, it brought their KH to 7 and they stopped shimmying and looking stressed all the time. But that's just me.

Link to comment
Share on other sites

On 4/29/2023 at 11:02 PM, AllFishNoBrakes said:

For me, I just focus on consistency. 

Yup. Totally agree and follow this practice for anything but specific breeding setups. Everything else gets acclimated to my tap/well water because consistency works more than anything else and it's also easier and less expensive than tweaking your water all the time.

The only caveat to this is obvious incompatibility scenarios. For instance, African Cichlids would probably not do ok in my water no matter how consistent I kept it.

Edited by tolstoy21
  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...