Water parameter issues after filter change and mystery snail hatching

[cotasm]

Hi, all.

I'm still fairly new to this (so, please be gentle 🙂), so I thought I should get some advice on something making me anxious...

About a year ago, I set up a non-planted 10 gallon tank for my son that initially had only a few platys. Eventually, we became fascinated with mystery snails and added a few of those. In the following months, I read and learned how to properly care for them, and I adjusted the pH, GH, and KH accordingly. I also made sure that they were being properly fed, had access to enough calcium, etc. They thrived after that.

A few weeks ago, we noticed an egg clutch on the lid. My son asked if we could leave it and see if they would hatch naturally without intervening with Tupperware and such. Water parameters were great at the time. Last Friday, I did about a 30-35 percent water change before leaving town for the weekend. When I plugged the AquaClear HoB filter back in, the motor hummed but the impeller wouldn't turn. I cleaned it as best I could, but it didn't fix it. Luckily for me, I had received my order from Aquarium Co-op a month earlier (the intention was to set up a tank of my own soon), which had a sponge filter, air pump, tubing, back flow valve, etc. So, I shifted gears and decided to use that filter as a replacement in my son's existing tank.

My original plan for setting up my own tank was to first run the sponge filter in my son's tank along with the HoB for a while to get the bacteria built up on the sponge filter media to eventually move to my new tank to shorten time to establish a cycle, but I never got around to setting it up that way. So, with the HoB no longer working in his tank, I set up and placed the new sponge filter in it. I wasn't sure if that would present a problem because it hadn't been sitting in a cycled tank, so (and maybe this wasn't the right move) I took the sponge filter media and bio media bag from the HoB filter and anchored it to the bottom of the tank as the new sponge filter ran. My thinking was that I was keeping the cycle from collapsing by temporarily keeping that media (and its bacteria) in the tank. So, off I went for my weekend road trip.

When I checked the tank after returning home (Monday), I noticed that many of the snails had hatched (no, I didn't crumble the clutch to expel the remaining snails and get rid of the clutch, but I guess I still could), and now there are a lot of cute buggers in the tank. I checked the water parameters because the pH sometimes dips a bit more than I'd like after a larger water change, which I bring back up gradually over several days with small amounts of sodium bicarbonate. This time, though, I noticed that the nitrites were measuring non-zero (but still very low). I did another test on Tuesday night (4-5 hours ago), and now I'm showing a more elevated level of nitrites and, now, ammonia also. It not terrible yet (I don't think); about 0.5ppm ammonia and about 0.5-1.0ppm nitrite, but they were zero before.

Because there are multiple variables involved here (e.g., water change, new filter that wasn't previously used in a cycled tank, HoB filter media still in tank, hatched snails, some debris from the clutch, etc.), I'm not sure how to pinpoint the cause of the worsening water. The trend is disturbing, though, because I wouldn't be surprised if it gets worse, especially if what I'm seeing is the beginning stages of a cycle crash.

Any advice on what my next steps should be to head off potential disaster?

Thanks so much for reading this far (I have an annoying habit of lengthy writing containing way more detail than is probably needed 😏) and for any guidance.

[Tony s]

On 5/8/2024 at 3:27 AM, cotasm said:

writing containing way more detail than is probably needed 😏

Na. It’s actually very helpful. Clears any ambiguity. The solution here is just water changes. Probably close to 50 percent. And use prime afterwards. Just keep constantly monitoring it. And when you see any issues. Do a water change. You can also add in a bit of bacteria. That could help. It’s definitely not going to hurt. 
 

it may try to get worse and crash but since you’d be monitoring, it can’t. Eventually it will stabilize. It may just be increased bioload causing the issue. And the sponge needs a chance to catch up. Not a big deal. 

[Tony s]

Your ph gh kh may dip for a bit because you’re adjusting your water to accommodate your snails. Over a few days to a few weeks, that shouldn’t be an issue either. It’s not permanent. And you have some time..you could test your ph every time, and redose your baking soda? To match the old ph.

[doktor zhivago]

2 things:

First: I think your filter will catch up and you'll be fine soon just some water changes as noted above. Lower pH is actually good for ammonia toxicity as it gets protonated easier and forms less toxic ammonium salts.

Second: Why is your ph dropping so much with a water change? What is the pH in your tank? What is the pH of your tap water? pH forms a complex with hardness and alkalinity. It's tough to move one without moving all the others. I would be very hesitant to try and chase ph around with baking soda without more context here.

 

 

[Tony s]

On 5/8/2024 at 3:27 AM, cotasm said:

we became fascinated with mystery snails and added a few of those. In the following months, I read and learned how to properly care for them, and I adjusted the pH, GH, and KH accordingly

@doktor zhivago she’s adjusting for the mystery snails. So any water change reverses her adjustment. 

Edited May 8 by Tony s

[doktor zhivago]

 

On 5/8/2024 at 9:38 AM, Tony s said:

@doktor zhivago she’s adjusting for the mystery snails. So any water change reverses her adjustment. 

OK I see now. I'm assuming the water is just very soft from the tap and the ph is crashing as the snails use up what little hardness there is. Maybe a buffer solution with aragonite or crushed coral would be more useful than chasing exact numbers? I just feel like that's a path to madness as raising pH naturally uses up alkalinity which lowers hardness which eventually lowers pH and the cycle continues forever...

[Tony s]

Right. I agree and always advocate using the water you have. But sometimes we find ourselves really liking something outside of our parameters. Whether it’s South America or African or in this case, mystery snails 😁 and we adjust. 
 

now, me, I have hard water. Which is fine. But I have high iron and iron bacteria in the well. I’m stuck using ro and remineralizing everything. Which is why I advocate the other way. 

[cotasm]

On 5/8/2024 at 5:34 AM, Tony s said:

The solution here is just water changes. Probably close to 50 percent. And use prime afterwards. Just keep constantly monitoring it. And when you see any issues. Do a water change. You can also add in a bit of bacteria. That could help.

Thank you for your help! 50% isn't too much? I've done that in more dire cases, but I generally try to stick to no more than 30% or so because I worry about the impact on the cycle, but if you think 50% is fine, I trust you more than myself on this matter. I just don't want to hurt whatever progress is made with the cycle (which I assume is delicate right now), but you're way more experienced than I am. 🙂 I do use Prime, so I'm covered there. Also, when you say "when you see any issues, do a water change", can you define "issues"? Would that be a specific level (i.e., high) of ammonia & nitrites, any non-zero level of ammonia & nitrites, or something else?

On 5/8/2024 at 5:54 AM, Tony s said:

you could test your ph every time, and redose your baking soda? To match the old ph.

Yea, that's basically what I do now. I don't need the baking soda every time, but every second or third change, I need to give the pH a little bump.

On 5/8/2024 at 6:38 AM, doktor zhivago said:

Lower pH is actually good for ammonia toxicity as it gets protonated easier and forms less toxic ammonium salts.

Thank you for the reply. I did not know that about the link between pH and ammonia toxicity (see, this is why I come here; I'm always learning interesting things like that 🙂). However, I tend to keep the pH higher side since the snails seemed to react much better to that in several ways, and the platys tolerate a higher pH well.

On 5/8/2024 at 6:38 AM, doktor zhivago said:

Why is your ph dropping so much with a water change? What is the pH in your tank? What is the pH of your tap water? pH forms a complex with hardness and alkalinity. It's tough to move one without moving all the others. I would be very hesitant to try and chase ph around with baking soda without more context here.

Well, I wouldn't say that it drops a lot with every water change, but after two larger or three smaller water changes, I find that the pH heads back toward 7.2-ish. I find that my snails do much better with a pH just above or below 8.0. I just tested my tap water again after your question about that (it's been a while since I did that, and I couldn't remember the exact reading), and it looks to be in the range of 7.0-7.2. I am generally aware of the buffering effect between hardness and alkalinity (just at a high level; not so much the hows & whys), which I assume is why my 8-ish pH tends to stay pretty stable in the tank water where I use wonder shells, a bit of crushed coral, and occasional baking soda. I assume (correct me if I'm wrong) that when I do a larger water change, that reduction in water hardness allows the pH to slip down.

Thank you both, @Tony s and @doktor zhivago for your responses. They were helpful and put my mind at ease a bit.

[Tony s]

On 5/8/2024 at 10:33 AM, cotasm said:

say "when you see any issues, do a water change", can you define "issues"

High ammonia or nitrites. 
 

and you can do huge water changes. Upwards of 75%. African cichlid keepers often do this. As long as the temperature difference is not too great. But a 50% works just fine usually. Sometimes the only way out of a jam is a huge water change. As long as you’re careful it’s okay 

[Tony s]

On 5/8/2024 at 10:33 AM, cotasm said:

I assume (correct me if I'm wrong) that when I do a larger water change, that reduction in water hardness allows the pH to slip down

It’s actually a reduction in the kh values that lowers your ph. Kh levels are the carbonates or the alkalinity. Where calcium and magnesium are your hardness and your gh values. The normal form of calcium is calcium carbonate. So it contains both. When you add in your baking soda. You’re actually raising the kh of your water. Which buffers your ph. 
 

and yeah. With every water change your water will want to revert back to 7 ph

[doktor zhivago]

On 5/8/2024 at 10:33 AM, cotasm said:

I assume (correct me if I'm wrong) that when I do a larger water change, that reduction in water hardness allows the pH to slip down.

Yeah this is probably what's happening. I was thinking your ph was much lower than 7.2 and was falling into the 5s or 6s which would indeed cause a cycle crash as the enzymes in beneficial bacteria stop working efficiently at those levels. I think you're doing everything right just gotta wait on that filter to catch up. 

 

Studying how pH interacts with water chemistry and microorganism biochemistry is like communicating with a Cthulhian old one. Its so complicated it leads only to insanity. Every aspect of interacts with every other aspect of in this giant web of cause and effect. That's why I just go the easy way with pH adjustments and buffer buffer buffer. 

[cotasm]

@Tony s: Great responses. I'm clearer on those things now. Thanks for the clarification/education!

[AllFishNoBrakes]

Considering you took the media out of the HOB and put it in the tank it leads me to believe that the tank is just catching up to the new bioload of the baby snails. Entirely possible that the sponge wasn’t entirely seeded too, but putting the old media in the tank was a good move. 
 

Test daily and water change through it. Should be no problem doing 50% water changes. I do that quite often on certain tanks. 

[cotasm]

On 5/8/2024 at 11:12 AM, AllFishNoBrakes said:

leads me to believe that the tank is just catching up to the new bioload of the baby snails.

That's what I was hoping. I just didn't realize it would happen so fast (the measurements that showed nitrite and ammonia happened within a day or so of the hatching).

On 5/8/2024 at 11:12 AM, AllFishNoBrakes said:

Entirely possible that the sponge wasn’t entirely seeded too

By "seeded", do you mean time in a cycled tank so that the bacteria could establish itself on the sponge filter media? If so, I'm sure that's part of it because it went straight from the box to the tank (well, I gave the filter media a rinse in tap water with Prime, though maybe I should have done that with tank water?). As I mentioned in the original post, the plan was to run the sponge filter in the tank with the HoB in preparation for using the sponge filter in a planted tank (for time for me doing that), which I assumed would quicken establishing the cycle in the new tank. But, alas, the HoB dying didn't give me much choice.

On 5/8/2024 at 11:12 AM, AllFishNoBrakes said:

putting the old media in the tank was a good move.

Yay. Great to hear that I did something right with my thinking. 🙂 I'm learning pretty quickly by reading a lot in these forums and other sites. Any idea how long I should leave the old HoB media in the tank before I can remove it?

Thanks so much for responding. It's all been very helpful.

[AllFishNoBrakes]

On 5/8/2024 at 10:04 AM, cotasm said:

By "seeded", do you mean time in a cycled tank so that the bacteria could establish itself on the sponge filter media?

Precisely. 
 

 

On 5/8/2024 at 10:04 AM, cotasm said:

If so, I'm sure that's part of it because it went straight from the box to the tank

Sorry I forgot that part. I always read through the entire post before I post anything. Must’ve forgotten. Still, that old media in the tank should’ve maintained all the beneficial bacteria, so you’re still way better off than new tank new filter. 
 

On 5/8/2024 at 10:04 AM, cotasm said:

Any idea how long I should leave the old HoB media in the tank before I can remove it?

Two weeks at minimum. Four would probably be even better. For now, leave it in until AT LEAST you’re not registering any ammonia or nitrite. Personally, I would leave it in there until you’re ready to start your own tank that the sponge was originally intended for. Might as well keep that seeded media to jump start your new tank 🙂 

[cotasm]

Topic adjacent... Do I need to do anything special for the baby snails in terms of feeding and care, or will they just manage on what I'm already putting in there for the other snails (i.e., blanched veggies, crab cuisine, occasional bits of cuttlebone to go along with a wonder shell, etc.)? Because I didn't use a breeder container (is that the term?), they're just in there with the other snails and platys. I read that the fish will sometimes pick off some of them, but I'm still seeing quite a few new snails, so I'm inclined to let nature take its course. In fact, a new clutch was laid last night (I got to see it happening!), though it's less than half the size of the one that just hatched. For this one, I might try moving it to a Tupperware container (set up appropriately with damp towels, air holes, etc.) just to try something new.

[cotasm]

A few last thoughts, and I promise not to bother too much more on this topic because you all have given me loads of good info... 🙂

1. I forgot to mention in the original post that I have a piece of Cholla wood in there that I added about 4 months ago. I did that for the sake of a very food-picky nerite snail that was in there for a while (I was told that they will munch on Cholla if algae is scarce) to help a lot more with the surface algae (and boy did it work wonders on the algae). However, it died recently. Not really unexpected; the place I got it gave it to me for free because it was much smaller than most, and they were unsure about its health, though it did fine in my tank until it died, which I understand happens a lot because they're all wild caught and don't always acclimate well (I was told survival past 6 months is 50/50). I know that Cholla wood can lower pH because of the tannins that get released (if I recall), but I boiled it first, which seemed to release most of that stuff into the boiling water. As such, I'm guessing that it's a non-issue or minimal impact, but I thought I'd mention it.
2. In the five days since switching from the HoB to the sponge filter, the water has become a little bit cloudy with a white haze. It's not bad, but I'm guessing that the reason that my water was crystal clear with the HoB is because I used custom filters and polishing pads that I cut into shape. With the sponge filter, it's just that one course mechanical filter, so I'm guessing it just isn't able to get the fine particles? Should I just leave it as is, or can something be done like maybe wrapping it in a finer filter?
3. I used to keep my bio media in the HoB (obviously), but now where do I keep it? As I mentioned in the original post, the HoB media is currently weighted to the bottom of the tank until I feel that I can remove it after the new sponge filter is seeded. I was using Matrix for the bio media, but with my large order from this site in preparation for my first planted tank, I picked up some bio rings that I'll probably switch to in the existing tank. Right now, I put some of those bio rings in a coarse bag in the tank next to the old Matrix media bag. But is that necessary, and if so, is keeping it in the tank in that manner effective, or is there a better way?

Thanks again!

[AllFishNoBrakes]

On 5/8/2024 at 10:40 AM, cotasm said:

I know that Cholla wood can lower pH because of the tannins that get released (if I recall),

It all depends on your kH. I have soft water, with lower pH, and little to no kH, and my blackwater tanks actually have the highest gH and kH. Why? Idk. I intentionally chuck in all kinds of botanicals and expected them to eat away at the kH and eventually drop the pH, yet that hasn’t been my personal experience. 

 

On 5/8/2024 at 10:40 AM, cotasm said:

so I'm guessing it just isn't able to get the fine particles?

Yup, that’s the downside to sponge filters. Especially coarse sponge filters. The “haze” or “cloudiness” could also be a bacteria bloom which is what you want right now. Personally, I’d just leave it. Don't wanna mess with too many things at once and you can always clear up any actual cloudiness from particulate matters later once the tank stabilizes. 

[Tony s]

On 5/8/2024 at 12:15 PM, cotasm said:

Topic adjacent... Do I need to do anything special for the baby snails in terms of feeding and care, or will they just manage on what I'm already putting in there for the other snails

If you have enough available tank algae or biofilm, they do just fine. Last year I raised about a hundred of them and did nothing at all for them. but I usually have enough (too much) algae.

[Tony s]

If you don’t have enough algae you could just supplement them with algae tabs and they’ll be fine 

And you could run both types of filters to catch the fines. Most of my tanks operate that way. hob as a primary and sponge as a backup and for aeration. But you’d have to replace your hob

Edited May 8 by Tony s

[cotasm]

Apologies for reviving my old post, but I have an update and questions...

The snails that hatched (wow, there are a lot more than I thought there were now that they're easier to see after some growth, but I guess that's a common reaction for a first-timer like me 🙂) seem to be doing fine. The original reason for my post was the sudden low measurement of ammonia and nitrites that appeared soon after the hatching combined with the urgent need to replace the HoB filter that failed around the same time (reminder: I replaced it with a new sponge filter that I had on hand, but I left the filter media from the HoB in the tank, which is still there, to help keep the cycle from crashing). The consensus seemed to be that it was probably just the cycle catching up to the new bio-load of the additional snails, which made sense and seemed to be the case in the days that followed.

As I'd hoped, a day or two after my last comment in this post, ammonia and nitrites measured zero (or very close to it, which was an improvement), so I figured I was in the clear. A few days ago, though, I started seeing low levels of ammonia and nitrites again (~.25ppm; maybe slightly higher, but not as high as .5ppm at this point). Luckily, it hasn't gotten worse. I'm worried that it will, but I don't want to do the typical newbie thing and overreact. I was about to do a water change (trying to decide between 30-50 percent), though now that I'm adding this comment, I'll probably hold off until I hear any responses.

Bonus question: I plan on keeping some of the new snails for my new tank that I'll be starting up soon. I may even keep an extra couple for my son's tank (the one they're in now). However, unlike others, I don't have another tank with inhabitants that can use them as snacks. My only thought at this point is to eventually see if the LFS in my area will take them or offer them up to people in some of my local social media groups. I'm wondering what others do. One thing is for sure, I probably won't let this happen again anytime soon (this one was purely unintentional, though we did let it happen once we noticed the clutch because we were curious if they would even hatch; we have since removed other clutches that were produced later).

Thanks!

[Tony s]

On 5/15/2024 at 7:42 PM, cotasm said:

My only thought at this point is to eventually see if the LFS in my area will take them

Yeah. That’s what I did. They would have offered credit but I wasn’t worried about that. I gave them 35. Then put a few in every other tank i had. That still left about 35 in my 75. They never seemed to add much to the bioload though. Or the 75 had a really good bb colony in it. 
 

same on the unintentional. But was really worth it in the lessons learned. 😀

[cotasm]

On 5/15/2024 at 8:02 PM, Tony s said:

They would have offered credit but I wasn’t worried about that.

Yea, I’ve read comments here about people who swap for store credit (like @AllFishNoBrakes with his angelfish), but like you, I don’t care about that either. I just want them to land somewhere useful. 

On 5/15/2024 at 8:02 PM, Tony s said:

same on the unintentional. But was really worth it in the lessons learned. 😀

Heh. Yea, I admit that I think it’s much cooler than I thought it would be, but now reality is setting in. They laid three more clutches, which I promptly removed. 🙂 If I ramp up my involvement in the hobby (substantially, I mean; I already have plans to start a second tank, but it would have to be more than that), then I’ll consider doing it again. 
 

Any thoughts on the low levels of ammonia and nitrite that have popped back up? My plan was to do a water change tomorrow, but because I did one not long ago and nitrates are fine, I’m tempted to do nothing for now and see if the issue works itself out, which I assume means it truly was the bacteria catching up to the additional snails and new filter. If the ammonia or nitrites go any higher (~.5ppm), then I’ll assume I have a cycle issue and should start the process of regular water changes until things settle. 

Thanks for the reply!

[Tony s]

On 5/16/2024 at 12:29 AM, cotasm said:

then I’ll assume I have a cycle issue and should start the process of regular water changes until things settle. 

Your cycle is fine but it may be adjusting to the higher bioload. My 75 was already full of angelfish, rainbow fish, and corys. So could probably process more. Yours will expand, may take a bit. I’d watch the nitrites closely, I believe those are more dangerous for your fish. You would have to change water to keep them down. Then use prime afterwards.