pH/GH/KH and Wonder Shell for Cardinal Tetras and Inverts

[Rube_Goldfish]

I'm still pretty new to the hobby; I have a ten gallon tank that's been running since the beginning of September 2021 and has had fish in it since early October 2021: two honey gouramis and five cardinal tetras (down from an original school of six).  My nitrogen cycle numbers are fine (consistently 0/0/10-20 ppm), and while I know my pH (8.2) is high for cardinals, it's very stable, and they haven't seemed to mind it too much.

In mid-November 2021 I put a nerite snail in the tank.  It just sat there that first day; I saw it on the glass the next morning, but by the end of the second day it was down on the gravel and never moved again.  In mid- and late-December I tried again, adding three Amano shrimp and one nerite snail, respectively.  I found one of the Amanos on the floor the morning of the second day (no lid; I've since added a pretty snug lid).  The other two Amanos seemed fine for about two weeks or so but have since disappeared.  I haven't seen them in about two months.  I know they're very good hiders, but I'm not optimistic that they're still alive.  The second nerite followed the pattern of the first one and also died within about 24-36 hours.

With all that long preamble, I bought an API GH/KH test kit and followed @Irene's advice on her YouTube video on pH/GH/KH, having theorized that that was the problem.  I ended up with a GH of 3 degrees and a KH of 14 degrees, and the pH is still that constant 8.2.  I have a water softener in my house, so I guess that's why the GH and KH don't "match".  I bought some Wonder Shell from the Co-Op to increase the GH, because I'd like to have snails and a couple Amanos in this tank (which I will shortly be upgrading to a 29 gallon).

So here are my questions: 1) Is the low GH the source of the problem I'm having with inverts?  2) If so, will Wonder Shell help?  3) Does Wonder Shell affect pH or KH at all? 4) Would raising the GH with Wonder Shell hurt the cardinal tetras and/or the honey gouramis?

[Mmiller2001]

There's several issues going on here.

1. The water softener can/ could cause problems. Some say it doesn't, some say it does. But ultimately, it removes Hardness and adds salt. I believe you can bypass the softener by using an outside spigot.

2. GH is a measure of magnesium and calcium in your water. I believe Wonder Shell only adds calcium but you'll have to do some research on that. I'm pretty sure though and I think it will raises KH also.

3. Although a 3dGH is on the lower side, it's not too low. However, snails and shrimp would be a bit more comfortable around 4 to 5dGH. 5dGH is where I'd go and that is fine for tetra as well.

4. Your KH is really high. I would look to drop that to 3dKH.

Grab a sample of pre softener water and test GH and KH just to see where your numbers are.

 

Edited February 14, 2022 by Mmiller2001

[Rube_Goldfish]

Ah, I didn't think of trying to get pre softener water!  Now I'll have to to pull out the manual and see how to do that...

Thanks!

[jwcarlson]

Typically your kitchen sink's "cold" water will be bypassed "around" the water softener.  Usually it's just a T off of the supply line to the softener, not some wild piping that's actually going "around" the unit.  Any outdoor spigots should be as well.  You'd have to investigate your plumbing to know for sure.  

I've started aging and pre-heating all of my aquarium water.  I put an additional bypass in for the laundry sink in the basement, which supplies my aging barrel water.  TDS is kind of an odd, nebulous number that doesn't mean much.  But my tap water is like ~600 TDS (gh=20, kh=18) and my "soft" water (from ion exchange unit) has TDS of about 1100.  I did some digging and apparently it exchanges two sodium for each mineral ion it removes, which increases the TDS.  I'm not worried about the TDS number per say... I'm just worried what all of those other ions might be doing to the fish.

For smaller tanks it can be as simple as a 5-gallon bucket, small heater (if needed), and an air stone in it.  Just set it up about 24 hours before you need it (filling with straight tap water). 

 

Saying all that simply to say that when I quit using a mix of tap + "soft" to get warm water for water changes my fish seemed happier.  At the same time learned that my tap water ages from about 7 pH to about 8 pH after 24 hours with air stone.

You'll want to set up a small container (like a quart) and do this aging process and test the water after that.  Don't worry about hardness before/after, that won't change.  And temp doesn't matter for the test (much).  What I did was run the tap for a couple minutes then fill a container.  Take your pH readings and write everything down.  Then add an airstone for about 8 hours (overnight is fine) and then test that pH again.  If it goes up, you're off-gasing CO2.  If it goes down you're off gasing something else which escapes me at the moment.  If it doesn't change at all, you're lucky.  

This aging also helps get rid of chlorine (but not chloramine to the best of my knowledge).

Edited February 14, 2022 by jwcarlson

[Rube_Goldfish]

About two months ago I did a pH test of straight-from-the-tap water, then set about a cup or half cup aside in a drinking glass to age overnight, and did another pH test (and then about 24 more hours later), though I didn't think to use an air stone or anything else.  I think the straight-from-the-tap pH was about 7.4, but I seem to have forgotten to write it down!  (duh!) The 24 and 48 hour numbers match my tank water, though, at 8.2.  I'll try again with the air stone, though, and write it all down this time!  Thanks!

[jwcarlson]

The air stone is mostly to hasten the process (and more important with larger quantities of water) for a small cup, just letting it set might be more or less "good enough".  you're really just looking for a rough idea.  I've seen a couple opinions, but I think the most prevalent pH swing "problem" was 0.4.  Meaning if it moves by more than 0.4 pH, you should be aging your water (these suggestions usually come from more sensitive fish, like discus, but I figure if it's pretty easy it would also be good for everything else).  Of course if you're changing 5 gallons in a 75 vs 5 gallons in a 10 gallon... this becomes less or more important, respectively.  I was doing twice daily 50% changes in my 10 gallon QT for a couple of weeks fighting bacterial infection (and a disrupted cycle).  A 5-gallon bucket seemed to age just fine in 12 hours with an air stone.  I've got a 30 gallon trash can in the basement that give 24 hours to just because of the added volume.

The main concern is pH pinball that can happen vs a nice, mostly steady one.  

 

Getting the specific numbers might be "nice", but I wouldn't be too worried about it.  I also checked my tank vs the aged water and found them to be the same (which makes sense considering the tank's water is, well, aged).

There's other stuff that changes tank water pH, though.

 

Good luck 🙂

[Rube_Goldfish]

In the beginning, I was thinking I'd use driftwood and maybe peat to bring the pH down, but my KH is high enough that I've long-since abandoned that plan and decided to console myself with a relentlessly stable, if high, pH, along with the "don't go chasing parameters" mantra.  That said, GH seemed a more reasonable parameter to chase, at least if it just meant dropping in a Wonder Shelll every so often.

I also meant to add:  I know an RO unit with remineralization would be the way to go for surefire parameters, but I don't think I can convince my better half that the cost and hassle is worth it, which is why I'm trying other means first.  Once I upgrade this 10 gallon to a 29, I plan on turning the 10 into a neocaridina tank, so I figured I'd sort out all my pH/GH/KH problems now before even getting to that point.  Plus, like I said, being able to have inverts in my little community tank without it being some sort of instant death.

[jwcarlson]

I think there's a lot of puffing about various water parameters when the reality is that if it's clean and stable that's probably 90% of it.  Dean is breeding wild discus in pH in the 8s.  Granted, his water is soft.  

I've got a shipment of discus arriving tomorrow, actually, and I talked with a bunch of discus purists who have made me feel very comfortable with growing out discus in HARD water (20 gh, 18 kh) with pH in the low 8s.  Granted, these are "domestic" discus, not wilds.  

It made me think that all of those parameters for other fish are probably similarly less important.  

Breeding (likely) a totally different animal.  But I'm not particularly worried about that personally.

[Mmiller2001]

On 2/14/2022 at 2:31 PM, Rube_Goldfish said:

"don't go chasing parameters" mantra

This is the worst advice the internet has to offer. When you chase numbers, you eventually learn how to control those numbers, which in return, teaches you how to set those numbers.

All you might need to do is add a bit of distilled water to your source water.

What's the GH and KH from your spigot?

[Torrey]

On 2/14/2022 at 2:48 PM, jwcarlson said:

I think there's a lot of puffing about various water parameters when the reality is that if it's clean and stable that's probably 90% of it.  Dean is breeding wild discus in pH in the 8s.  Granted, his water is soft.  

I've got a shipment of discus arriving tomorrow, actually, and I talked with a bunch of discus purists who have made me feel very comfortable with growing out discus in HARD water (20 gh, 18 kh) with pH in the low 8s.  Granted, these are "domestic" discus, not wilds.  

It made me think that all of those parameters for other fish are probably similarly less important.  

Breeding (likely) a totally different animal.  But I'm not particularly worried about that personally.

I bred discus in the high desert (hard water, liquid calcium water) and while the adult discus thrived in my 8.2 pH liquid rock, the eggs would basically absorb too much calcium and the fry couldn't escape. 

As long as you are not planning on breeding, the majority of discus don't care as much as we humans say they do.

If you want to breed, and have the fry viable, the options are RO to reduce the mineral components, or have a water prep tank with calcium hogs. Dean's water is naturally soft so his discus fry hatch.

My water was not, so I kept a LOT of peat moss in my breeding tanks and essentially created a dark water system that wouldn't drop any lower than 6.8 pH, but wasn't calcium saturated either 

[jwcarlson]

Yep, that's my understanding after talking with enough people.  At this point I am uninterested in breeding and am getting 2.5" fish (tomorrow by plane).  I could see wanting to breed them someday, but that's a minimum of a year or year and a half away from them being mature enough.  Last thing I need is hundreds of little tiny discus. 🤣

[Torrey]

True! My first successful hatch left me with 300 fry and 2 pairs of happy, harried, discuss parents. 

[Rube_Goldfish]

I poked through my water softener manual, but I'm not sure I'll be able to bypass it.  I haven't ruled it out, yet, but they didn't make it easy.  Unfortunately real life got in the way and I wasn't able to do GH/KH testing on my tap water yesterday, either.

In the meantime, since I know Wonder Shell will raise my GH, but my concerns are a) will it affect my KH and/or pH; and b) will it raise it too much or too fast for the tetras and gouramis, I think I'll draw some tap water into a bucket, condition it with Prime, then drop the Wonder Shell in there and test it after 24 hours or so.  Depending on those results, I could "dose" my tank with the Wonder Shell'd water in as big or small an increment as makes sense.

Does that sound reasonable?

Long term, I may just suck it up and use LFS/grocery store RO or distilled water, re-mineralized.  That shouldn't be too expensive with only a 10 and 29 gallon tank, and even bi-weekly 25% water changes would only be about 10 gallons, which would be a couple bucks.  My LFS uses an RO system, so maybe that's just what the water around here is like.

[Rube_Goldfish]

On 2/15/2022 at 4:27 PM, Rube_Goldfish said:

I think I'll draw some tap water into a bucket, condition it with Prime, then drop the Wonder Shell in there and test it after 24 hours or so.  Depending on those results, I could "dose" my tank with the Wonder Shell'd water in as big or small an increment as makes sense.

Okay, I did that, more or less (I can't remember if I used Prime or not).  Anyway, I put about 2.5 gallons in a bucket, stuck a heater in there, turned the heater on (77F) the next morning, took three 5 mL samples about eight hours later, and dropped an extra small Wonder Shell in the bucket.  The bucket had a lid sort of loosely resting on top (to allow space for the heater's wire).  I took three more 5 mL samples every day after that for three more days.

I wanted to know a) would the KH and/or pH go up?  And b) how fast would the GH go up?

Day 0 (before the addition of the Wonder Shell): pH 8.0, GH 1-2, KH 14

Day 1: pH 8.2, GH 5-6, KH 15

Day 2: pH 8.0, GH 8, KH 15-16

Day 3: pH 8.2, GH 10, KH 17

A few thoughts: I'm not sure why the pH seemed to go up and down, but I'm attributing it to human error.  My pH out of the tap (after 24 hour CO2 off-gassing) is 8.2, and the tank has consistently read 8.2 for months.  Similarly, where I put a range, I was trying to capture where I screwed up and accidentally dripped some extra drops into the tester vial.  Amateur chromatography is not my forte!

I attribute the rising KH mostly to evaporation.  That's a confounding variable I hadn't considered, so I didn't think to record that.  But while the bucket has a lid, it's only loosely on, and the air in the room is kind of dry and about seven degrees cooler.

Most importantly, I'm satisfied that the GH rose slowly enough that the cardinal tetras, honey gouramis, and plants could deal with the change.  Especially since it's a ten gallon tank, not a half-filled five gallon bucket, so the rate of change of GH ought to be even slower.

I'll drop a Wonder Shell into the tank, then keep an eye on all these parameters over the next few days and weeks, doing water changes as necessary.  Once the tanks has reached 6 or 8 dGH, I'll try snails and Amano shrimp again.  Anyone see any problems with that plan?

On a semi-related note: I expect to have a lot more questions.  What's the etiquette here?  Make a new thread every time a new question occurs to me?

Thanks so much for all your help so far!