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Just discovered my kH is 0-1 (!!!) and tank parameters differ greatly from my tap water.. do I need to adjust kH/Ph??

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SPECS:
  • 15 gallon
  • low tech/no CO2
  • filtration - tetra 20 gal power filter plus small pump for circulation
  • light - Current Satellite 18/24" LED (so medium/low light?)
  • substrate - bare bottom
  • hardscape - medium piece of driftwood that I've used in diff tanks over the last ~15 years
  • tank has been cycled and running for ~3 years
LIVESTOCK/PLANTS:
  • heavily planted with slow growing/low light plants (java fern w./anubias/crypt/buce)
  • Ferts: none
  • livestock: breeding colony recently cut back to ~15 male tiger endlers, 1 hillstream loach, misc trumpet snails/bladder snails,1 recently added plakat betta, added 3 amano shrimp 3 days ago
STORY:
After not touching the tank for almost a year (except 25% wc every two weeks) I wound up with a crazy hair algae takeover. When I acquired the betta last week, I pulled out almost all of the algae, unclogged my severely clogged filter, restoring water flow that had gone down to a trickle (yikes!), and added a small powerhead for MUCH improved circulation to benefit both plants and fish. My Kh had always been decent and my plants had done a good job soaking up the nitrate, but I ran water tests and was shocked!

RECENT PARAMETERS:
  • (temp - 76)
  • AM - 0
  • NI - 0
  • NA - 60
  • Kh - 0-1
  • pH - 6.4
Not only were my nitrates high in spite of the plants (!!), but pH was low (which I know can be related), and Kh was nonexistent!
Problem is, the pH of the the tap water I use is through the roof:

TAP WATER PARAMETERS:
  • AM - 0
  • NI - 0
  • NA - 0-10
  • ph - 8.4+
  • Kh - 4
I did a 50% wc to reduce nitrate, hoping the kH 4 of the tap water would prevent a pH swing, but I was wrong.
Parameters immediately post wc were:
  • NA - ~15
  • Ph - 7.2 (!!!!!!!!!!!!)
Fish acted like it was nbd, and actually the livestock seemed to appreciate the higher pH. Snails came back to life and started grazing. But I know that's a crazy shock.
Even wilder, the next morning, pH had gone back down to:
  • pH - 6.6
  • Kh - 2
These swings have got to be tough on my critters and plants... what should I do about it??
How can I continue to safely do water changes across a 2 point pH difference with my current Kh being so low?
I recently learned tap water pH can shift as much as a point after resting for 12 hrs and off-gassing.. should I be aging my tap water?
I was reading about aklaline buffers and phosphate vs calcium based ones.. I don't want to riase the kH too much for the sake of my shrimp, but I also don't want another algae explosion from phosphate
I would like to establish kH of 3 (for the shrimp and plants, and moderate stability), and a pH around 7 if that's possible... ??

Any advice would be most welcome!

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Stop worrying about pH. Focus on hardness.

Are you testing with a liquid kit or strips? Strips aren't reliable when it comes to kH or gH.

The parameters in your tank are fine for what you're keeping. Though, you'd likely benefit from having an actual substrate like sand or fine gravel. There'd be more surface area for beneficial bacteria, your Trumpet Snails would have something to burrow in, etc.

Driftwood is likely the reason you're seeing kH drop from tap to tank. Wood can release tannic acid for years and years. I've got a piece that I've been using since 2008 or so that will drop my 3-4 kH tap water to near 0 in a matter of hours. Still. All these years later. You could add baking soda but it likely won't make much of a difference and would be a waste of time. Just focus on stability and you'll be fine. Do 20% weekly water changes and maybe add the freshly Primed (before adding it to the tank) tap water back over the course of 15 minutes or so. That will reduce any potential parameter swings from being a big deal.

Definitely do weekly water changes. Your plants are slow growing and obviously can't keep up with the nitrates in your system. Water changes fix that.
 

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Discussion Starter · #3 · (Edited)
Stop worrying about pH. Focus on hardness.
...
Driftwood is likely the reason you're seeing kH drop from tap to tank. Wood can release tannic acid for years and years.
...
Definitely do weekly water changes.

Thanks v much for the reply!

Why should I not be worried about pH? Don't big changes to pH majorly stress fish and plants? :unsure::unsure::unsure:

Maybe you're saying to focus on Kh to stabilize the situation, which would make sense

I've always used the API master test kit. Kh readings are definitive, but I'm having a hard time interpreting the Gh test results on both tap and tank water. Might take water to my LFS and get their thoughts if it's an important part of the picture.

Not concerned about substrate - the biofilter has always been rock solid, and I don't want to encourage the snails. They have a lot of plants and wood to chew. The bare bottom lets me do a really thorough poop vac.

Good call about the driftwood, I didn't realize it could leach that long! Thing is that piece has been in the tank for a long time, and kH used to be about 4. I might have been doing more frequent water changes at that time though, which would explain the difference.

So overall I think you're right that the answer is probably just water changes. That would bring my tank closer to my source parameters in any event.
The only part of that I wouldn't be thrilled with is the pH, since I think my tap pH of 8.4 is less ideal for my plants and critters?
 

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Why should I not be worried about pH? Don't big changes to pH majorly stress fish and plants? :unsure::unsure::unsure:
kH does help determine pH. But it's osmotic pressure that's really more important than the acidity of your water. Feel free to search around the forum for more details.

The bare bottom lets me do a really thorough poop vac.
Substrate isn't a necessity, per se, but it is a planted tank. It would allow the waste from your livestock to make its way into the substrate to be utilized by plants. Having substrate doesn't inhibit one from removing detritus at all - which is why millions of us use substrate. To each their own, obviously, but looking at the issues you're experiencing (like high nitrates), extreme algae, parameter instability leads me to believe you'd benefit from actually having a substrate for plants.

I don't want to encourage the snails. They have a lot of plants and wood to chew.
Malaysian Trumpet Snails are a burrowing species, so they need something to burrow in. Having substrate doesn't "encourage" snails - it's food supply that determines their population size. Keep your feeding and decaying plant matter in check and you won't have a ton of snails of any variety.

I'm having a hard time interpreting the Gh test results on both tap and tank water.
May want to try a different brand of test kit. Sera's kH and gH kits are relatively affordable and are much easier to read than API.

So overall I think you're right that the answer is probably just water changes. That would bring my tank closer to my source parameters in any event.
The only part of that I wouldn't be thrilled with is the pH, since I think my tap pH of 8.4 is less ideal for my plants and critters?
If your tank's kH is dropping quickly like this, doing weekly water changes isn't going to make too much of a difference. It will, however, result in better tank stability. Your kH, and therefore pH, will be lower in your tank because of the driftwood regardless. Doing weekly water changes, as previously mentioned, will allow you to remove waste and keep parameters more stable.

The livestock and plants you're keeping will be fine with a pH higher than your tank currently has. Just focus on stability.

If you want to learn more about tank stability and how livestock adjust, spend some time in the Tank Journals section. Search through the tanks of longtime hobbyists who have parameters similar to yours or livestock similar to yours. You'll see how things adapt and thrive.
 
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