I've been lurking for a bit, sorry my first post has to be a problem. I've got a 55l cube tank that's been running for a year with no major losses apart from an old betta and 2 recent snails. The tank's got 4 harlequin rasboras, 6 tetras, a betta, a kuli loach, a platy, and a tiny platy fry, plus a bunch of healthy-looking plants and virtually no algae. I do a 25% water change every week, never miss one.
API test results are: 6 PH (could be lower, that's the lowest on the chart), 1 ammonia (down from 2-4 after water changes), 0 nitrates, and 0 nitrites. I did some tweaking a month or two ago to get rid of green water algae - more aggressive water changes, scrubbing the filter with aquarium water, and adding more plants. I also changed up some rocks and added a new betta 3 weeks ago.
My problem is one platy looks great but spends a lot of time at the bottom, not really coming up to eat, and I just lost 2 snails that had been in the tank for 2 months. I'm wondering if the 0 algae could be the cause, but I'm not sure. I've read snails shouldn't starve in a planted tank, but mine never seemed to go near the plants, just the glass and rocks.
I used to use test strips, and I thought everything was fine with 0 nitrates, nitrites, and low PH, but now I'm reading up on it, and it seems odd that I never detected nitrates in the past. I'm thinking maybe the test strips were rubbish, but the new API kit shows the same results. I stopped using ammonia test strips 4 months ago when they ran out, and they always showed 0.
Now I'm panicking seeing this ammonia and 0 nitrates, so either the cycle has crashed or I never had a cycle to begin with. I've done 25% water changes each day for the past 4 days, and the ammonia has gone down from 2/4 to 1. From what I've read, it's possible that my ultra-low PH and plants are keeping the fish alive by eating ammonia/keeping the balance of NH4/NH3 on the side of harmless ammonium.
But I'm stuck - if my low PH is keeping the fish alive, I don't want to raise it, but I need to raise it to get the tank to cycle properly. It's a catch-22. I've got a few options:
One is to try and cycle the tank with this low PH over 4 weeks, doing water changes if the ammonia gets too high and using Prime each day. But I've read that bacteria won't like the low PH, so I'm not sure if this will work.
Another option is to use crushed coral or something to raise the PH slowly, dose with Prime, and try to start a proper fish-in cycle.
Or maybe there's another option I haven't thought of? I'm not sure how long the ammonia has been there since I haven't tested for it in months.
A year old tank with unclear results: was it properly cycled?
Re: A year old tank with unclear results: was it properly cycled?
I think I see where you're coming from with your concerns about ammonia, but with a pH as low as 6, the ammonia is mostly in the non-toxic form. I've been reading up on this, and it seems that the amount of toxic ammonia versus non-toxic ammonium depends on both temperature and pH. Apparently, our test kits measure both, but there are calculators that can break it down further.
Using your numbers, with a pH of 6 and 1 ppm ammonia at 25 degrees Celsius, the free ammonia is only about 0.0006 ppm, which is well below the 0.05 ppm 'safe' limit. Even at 4 ppm, the free ammonia would still be relatively low at 0.0023 ppm. However, I do think we need to figure out why your ammonia levels were so high before you started doing daily water changes.
I'm not too concerned about the zero nitrate reading, though. I've got zero nitrates in my tank, and I think it's because my tap water has low nitrates and I've got a lot of plants. The plants seem to be taking care of any ammonia produced by the fish and plants, converting it into protein rather than nitrite or nitrate.
It's possible that you've got very soft water, which could be causing some issues. Platies are typically hard water fish, so they might be struggling with the low calcium levels in your water. This could be stressing them out and making them more susceptible to disease. I think it's generally better to keep fish that are adapted to the local water conditions rather than trying to alter the water to suit a particular species. The other fish you've got seem to be soft water fish, so they should be fine in your tap water.
I'm a bit stumped as to why your ammonia levels were so high, though. Even if the bacteria aren't doing their job, the plants should be removing some of the ammonia. Can you tell me more about the plants you've got in the tank, and whether you've added any new ones recently? Have you ever added any chemicals to the tank apart from water conditioner or plant fertiliser?
One thing that did catch my eye, though, is that you've got a betta in with a bunch of other fish. Bettas are generally solitary, so it's best to keep them alone. If your new betta dies, I'd advise against getting another one for this tank. If you ever set up a new tank, maybe around 25 litres, that would be a good size for a betta on its own. The harlequins, tetras, and kuhli loach would all do better in larger groups, but your tank is a bit too small for that.
Using your numbers, with a pH of 6 and 1 ppm ammonia at 25 degrees Celsius, the free ammonia is only about 0.0006 ppm, which is well below the 0.05 ppm 'safe' limit. Even at 4 ppm, the free ammonia would still be relatively low at 0.0023 ppm. However, I do think we need to figure out why your ammonia levels were so high before you started doing daily water changes.
I'm not too concerned about the zero nitrate reading, though. I've got zero nitrates in my tank, and I think it's because my tap water has low nitrates and I've got a lot of plants. The plants seem to be taking care of any ammonia produced by the fish and plants, converting it into protein rather than nitrite or nitrate.
It's possible that you've got very soft water, which could be causing some issues. Platies are typically hard water fish, so they might be struggling with the low calcium levels in your water. This could be stressing them out and making them more susceptible to disease. I think it's generally better to keep fish that are adapted to the local water conditions rather than trying to alter the water to suit a particular species. The other fish you've got seem to be soft water fish, so they should be fine in your tap water.
I'm a bit stumped as to why your ammonia levels were so high, though. Even if the bacteria aren't doing their job, the plants should be removing some of the ammonia. Can you tell me more about the plants you've got in the tank, and whether you've added any new ones recently? Have you ever added any chemicals to the tank apart from water conditioner or plant fertiliser?
One thing that did catch my eye, though, is that you've got a betta in with a bunch of other fish. Bettas are generally solitary, so it's best to keep them alone. If your new betta dies, I'd advise against getting another one for this tank. If you ever set up a new tank, maybe around 25 litres, that would be a good size for a betta on its own. The harlequins, tetras, and kuhli loach would all do better in larger groups, but your tank is a bit too small for that.
Re: A year old tank with unclear results: was it properly cycled?
Thanks for your detailed reply. I really appreciate the insight on the ammonia thing. I did remove some decaying plant matter recently and I had a snail decaying in the tank for a few days. Some of the moss I added might be dying or just changed color, so I'll probably remove that too. However, I've spoken to people who don't think that could cause the ammonia levels I had.
I'm still trying to wrap my head around the tank cycle situation. Is it possible to have a tank for a year with this many fish and it not be cycled? I've read a lot about aquariums, but I've never come across anything like this. I've used test strips many times, and I've never recorded any nitrates or nitrites. I know I didn't understand the results, but it's hard to believe I never had any.
I do have a good amount of plants, but I thought they wouldn't be enough to remove the waste from all these fish. I've added some algae removal products, QuickClear, and Leaf Zone recently. I also stopped adding bacteria supplements a while back and switched to API QuickStart due to the recent problems.
Regarding the betta, I understand your point, but I've read a lot of different opinions on this. My betta doesn't seem to be aggressive, and the other fish ignore him. My previous betta had a fin nipper, so I rehomed him. I appreciate your view, and I'll definitely consider it for future projects.
I also found out that neon tetras are better off in larger tanks with larger schools, despite their size. It's good to know for future projects.
One thing I didn't mention earlier is that our first fish were platys born in a local pet store. They bred, and we ended up with about 15. I gave most of them away, but these two survivors have spent their whole life in the tank. I know you mentioned that platies prefer hard water, but they've grown up in this tank. However, I think our tap water pH is 6.8, and the aquarium pH is 6, so it's possible that the pH has dropped recently, causing problems. I've ordered a GH/KH test kit to try to figure out what's going on with the water hardness.
I just got some new test strips in the post, and they're showing 0 ammonia, 0 hardness, and the lowest pH. It's adding to the confusion. The product is not as good as the API kit, but it's making me doubt the results.
I'm still trying to wrap my head around the tank cycle situation. Is it possible to have a tank for a year with this many fish and it not be cycled? I've read a lot about aquariums, but I've never come across anything like this. I've used test strips many times, and I've never recorded any nitrates or nitrites. I know I didn't understand the results, but it's hard to believe I never had any.
I do have a good amount of plants, but I thought they wouldn't be enough to remove the waste from all these fish. I've added some algae removal products, QuickClear, and Leaf Zone recently. I also stopped adding bacteria supplements a while back and switched to API QuickStart due to the recent problems.
Regarding the betta, I understand your point, but I've read a lot of different opinions on this. My betta doesn't seem to be aggressive, and the other fish ignore him. My previous betta had a fin nipper, so I rehomed him. I appreciate your view, and I'll definitely consider it for future projects.
I also found out that neon tetras are better off in larger tanks with larger schools, despite their size. It's good to know for future projects.
One thing I didn't mention earlier is that our first fish were platys born in a local pet store. They bred, and we ended up with about 15. I gave most of them away, but these two survivors have spent their whole life in the tank. I know you mentioned that platies prefer hard water, but they've grown up in this tank. However, I think our tap water pH is 6.8, and the aquarium pH is 6, so it's possible that the pH has dropped recently, causing problems. I've ordered a GH/KH test kit to try to figure out what's going on with the water hardness.
I just got some new test strips in the post, and they're showing 0 ammonia, 0 hardness, and the lowest pH. It's adding to the confusion. The product is not as good as the API kit, but it's making me doubt the results.
Re: A year old tank with unclear results: was it properly cycled?
It's indeed puzzling that your tank hasn't cycled despite having it for a year with that many fish. However, I do agree with sSjey that plants can remove ammonia, especially if you have a good amount of them. Floating plants, in particular, are excellent at this as they're near the surface and can get CO2 from the air. I've had experience with quarantining new fish in somewhat overstocked conditions, and with just a couple of bunches of elodea and a surface covered with floating plants, I never see a trace of ammonia or nitrite.
If you're interested in verifying your tap water's hardness, you can check Scottish Water's website, although they don't make it easy to find. I can guide you on how to find it if you'd like. It would be interesting to compare your tap and tank water results.
Regarding your water change schedule, you mentioned you used to do 25% water changes until you tested for ammonia. How often did you do these changes? I'm curious because soft water often has low KH, which buffers the water against pH changes. If KH is very low, it can get used up, leaving nothing to stop pH from falling. I've experienced this myself in the past, where my pH plummeted due to low KH and infrequent water changes. I started doing weekly water changes instead of monthly, and I haven't had a pH drop since.
I also suspect that the algae removal stuff might have caused the problem. API Quick Start does contain the right species of ammonia eaters, but it's worth keeping an eye on nitrite levels as well. If you use the whole bottle, you might want to consider Tetra Safe Start for your next purchase.
It's also worth noting that your platy's behavior, spending most of its time at the bottom, could be related to the low pH and soft water. As sSjey mentioned, platies are hard water fish and might be stressed in soft water conditions.
If you're interested in verifying your tap water's hardness, you can check Scottish Water's website, although they don't make it easy to find. I can guide you on how to find it if you'd like. It would be interesting to compare your tap and tank water results.
Regarding your water change schedule, you mentioned you used to do 25% water changes until you tested for ammonia. How often did you do these changes? I'm curious because soft water often has low KH, which buffers the water against pH changes. If KH is very low, it can get used up, leaving nothing to stop pH from falling. I've experienced this myself in the past, where my pH plummeted due to low KH and infrequent water changes. I started doing weekly water changes instead of monthly, and I haven't had a pH drop since.
I also suspect that the algae removal stuff might have caused the problem. API Quick Start does contain the right species of ammonia eaters, but it's worth keeping an eye on nitrite levels as well. If you use the whole bottle, you might want to consider Tetra Safe Start for your next purchase.
It's also worth noting that your platy's behavior, spending most of its time at the bottom, could be related to the low pH and soft water. As sSjey mentioned, platies are hard water fish and might be stressed in soft water conditions.
Re: A year old tank with unclear results: was it properly cycled?
I think there's some misunderstanding here. With live plants, they should keep nitrite and nitrate levels in check, right? So, I'm not sure what role Seachem Prime is playing in this situation - it seems to me that it's just masking the issue rather than addressing it. And using it daily as some sort of preventative measure doesn't seem like the best approach to me.
Re: A year old tank with unclear results: was it properly cycled?
I'm having trouble wrapping my head around this situation, but I think I've got some ideas. If you're dealing with ammonia, the best way to tackle it is with water changes - assuming your tap water is ammonia-free, of course. I'd recommend doing daily water changes until the ammonia levels drop to zero, then see how things play out.
I'm still having a hard time believing that your tank isn't cycled after all this time. It's possible that something happened to disrupt the bacteria colonies, but it's unlikely that one set of bacteria would be affected and not the other. And with all the plants you have, they should be taking up ammonia like it's their job - they're actually faster at it than the bacteria.
One thing that might be worth trying is adding some floating plants to the mix. I've had great luck with red root floater and salvinia in the past - they're tiny, but they pack a punch when it comes to removing ammonia. And the fish love having something overhead to hide under, whether it's a big ol' Amazon frogbit or a water sprite.
I'm still having a hard time believing that your tank isn't cycled after all this time. It's possible that something happened to disrupt the bacteria colonies, but it's unlikely that one set of bacteria would be affected and not the other. And with all the plants you have, they should be taking up ammonia like it's their job - they're actually faster at it than the bacteria.
One thing that might be worth trying is adding some floating plants to the mix. I've had great luck with red root floater and salvinia in the past - they're tiny, but they pack a punch when it comes to removing ammonia. And the fish love having something overhead to hide under, whether it's a big ol' Amazon frogbit or a water sprite.
Re: A year old tank with unclear results: was it properly cycled?
Just got my GH/KH kit, did a full test. Found it a bit fiddly, but I think I got it right. Not entirely sure it makes sense for my tank GH to be higher than the source water, so I might retest tomorrow to confirm.
Source water:
0 ammonia, pH 6.6-6.8, GH 35.8 (2 drops), KH 35.8-53.7 (2-3 drops)
Tank water:
0.25-0.5 ammonia (was 0.5 yesterday), pH 6.0, GH 53.7 (3 drops), KH 0/1 drop.
Source water:
0 ammonia, pH 6.6-6.8, GH 35.8 (2 drops), KH 35.8-53.7 (2-3 drops)
Tank water:
0.25-0.5 ammonia (was 0.5 yesterday), pH 6.0, GH 53.7 (3 drops), KH 0/1 drop.
Re: A year old tank with unclear results: was it properly cycled?
I think I've worked out what's going on with the KH and pH in my tank. The KH is lower in the tank water because it's being used up, which would allow the pH to drop.
I'm a bit puzzled by the GH reading though - it could be something in the tank, but you'd expect that to affect the KH as well. Maybe the GH is borderline 2 to 3, I find the colour change tricky to see when only a couple of drops are added. The KH colour change is much easier to spot.
One thing that might help with reading the GH and KH is to put the test tube on something white and look down into the tube between each drop. I found this makes the colour more intense and easier to read, especially with soft water.
I'm a bit puzzled by the GH reading though - it could be something in the tank, but you'd expect that to affect the KH as well. Maybe the GH is borderline 2 to 3, I find the colour change tricky to see when only a couple of drops are added. The KH colour change is much easier to spot.
One thing that might help with reading the GH and KH is to put the test tube on something white and look down into the tube between each drop. I found this makes the colour more intense and easier to read, especially with soft water.
Re: A year old tank with unclear results: was it properly cycled?
So the platy seems a bit better the past couple of days, not sure if that's significant yet but I did notice something. My water changes have brought down the ammonia readings as expected, currently it's 0.25. However, the pH and KH are still stuck at the bottom of the scale.
This is making me think that the pH in the tank must be really low, as the water changes aren't making a visible impact. I mean, if it was 4 and now it's 5.5 or 6, I'd expect to see some change after 4 days of 25% daily changes and a single 50% change. It's not like I've made a huge change, just a gradual one.
I'm starting to wonder if the pH crashed so low that it made the platy miserable and killed off the bacteria. There was a lot of dead plant material in the tank, plus the dead snails. It's possible that this caused a chain reaction that's still affecting the tank.
This is making me think that the pH in the tank must be really low, as the water changes aren't making a visible impact. I mean, if it was 4 and now it's 5.5 or 6, I'd expect to see some change after 4 days of 25% daily changes and a single 50% change. It's not like I've made a huge change, just a gradual one.
I'm starting to wonder if the pH crashed so low that it made the platy miserable and killed off the bacteria. There was a lot of dead plant material in the tank, plus the dead snails. It's possible that this caused a chain reaction that's still affecting the tank.
Re: A year old tank with unclear results: was it properly cycled?
A few observations. First, you have very soft water, so none of what is occurring is in the least "strange." The GH and KH are buffers for the pH but here they cannot prevent the lowering of the pH. Regardless of what in the past may have done or not done to the pH, it is going to become more acidic. If you keep soft water fish species, that is absolutely fine.
Your platy is in trouble though, and it will not live long, or if it does, it will be continually plagued. Livebearers need moderately hard water. But you have soft water fish that do not want it higher.
Also, you have plants, and they grab the ammonia faster than the nitrifying bacteria. But all else considered, this is not a problem here. You do not need to be doing water changes beyond once a week, 50-60%. And Prime is not needed.
Your platy is in trouble though, and it will not live long, or if it does, it will be continually plagued. Livebearers need moderately hard water. But you have soft water fish that do not want it higher.
Also, you have plants, and they grab the ammonia faster than the nitrifying bacteria. But all else considered, this is not a problem here. You do not need to be doing water changes beyond once a week, 50-60%. And Prime is not needed.