Established filter - but nitrite readings? Plants killed off my BB maybe?

[AdoraBelle Dearheart]

Hi, hoping someone can help me figure out what might be going on in my tank.

Background: Have had two and a half tanks for around a year, both tanks were fully cycled, usual levels ammonia 0, nitrite 0, ammonia between 5-10, heavily planted. Thanks to worms in my livebearers, I moved all fish and shrimp to one tank while medicating. Anti bacteria med did cause a mini cycle, but easily got back under control within two days. In the meantime I stripped down and bleached the second tank and all equipment, except for filters which were placed on other tanks to try to keep them cycled.

2nd tank was set up again hastily as treatment finished when I started to lose shrimp, and it seems four plants I bought from my LFS had come from outside the EU and so been treated with a pesticide that affects chitin production in shrimp, preventing them from moulting and proving fatal. Moving them out of that tank became urgent, despite removing the plants, I was still having losses.

Set up second tank. New sand, clean unused driftwood and stones, and some new plants, grown in-vitro so shrimp safe. I'm aware that it's tough on shrimp not to be in an established tank with plenty of biofilm and algae, but I have no choice now, and I'm feeding them hikari shrimp cuisine and snowflake food.

Tuesday
planted;

Echinodorus 'rose'
Limnophila sessiliflora
Rotala 'bonsai'
Shrimp moved in Tuesday night.
I'd added a double sponge filter that also has chambers with ceramic rings, that had run on the other 15 gallon for a year. Well stocked tank with guppies, otos and shrimp, so I expected it to be fully cycled and not to have issues with the cycle.

Moved a few of the guppies over too, two adults, a sub adult and two young fry, along with the 40-50 shrimp.

Wednesday
Added small pot of amazon frogbit, and hydrocotyle tripartitia 'Japan'
Ten pm wednesday, did a water test. Zero ammonia, nitrates 5, but there was a slight purple tinge to the nitrite tube. Around 0.25. Did a 50% water change and tested again, nitrite back to zero.

Thursday
Water test around 3pm, ammonia still showing zero, but nitrites very slightly there again, probably less than 0.25ppm, but still not zero, especially when compared to the test from last night, as shown in this photo. Hard to see in a photo, but ammonia zero, last night's post water change nitrites zero, today, nitrites above zero, but < 0.25.

Did a 70% water change, syphoned any plant matter from the sand, and cleaned the sponge filter gently, just to remove the plant bits and pieces that had gathered on the sponges.

Is it possible that my established sponge filter I've been running in a well stocked tank for a year, is uncycled because the plants were taking up any ammonia and starving the bacteria? Am I basically putting my cherry shrimp through a brand new tank cycle?

I don't dare transfer any additional plants from my other tanks, since they may be contaminated by the pesticide the new plants bought in. I'm not sure why nitrites are showing up so quickly either. I've only fed the guppies lightly, and dropped in small but frequent amounts of food for the shrimp because I have to - they have no biofilm or algae to eat anywhere else in the tank.

Am I basically cycling from scratch here? Any suggestions for how to handle this? I've never cycled a tank with livestock in it before, let alone creatures as sensitive as shrimp, especially when I need to feed them well as they have no other food source yet.
Should I fertilise the plants to help them grow faster and take up ammonia? How have some of my ammonia bacteria survived, since I'm getting nitrite readings, yet the nitrite eating bacteria haven't?
Any suggestions for food for the shrimp that isn't going to spike ammonia?
Do I leave the guppies in to help cycle the sponge filter, or move them out again to keep the bioload even lower for the shrimp and let the plants do the work?

 

[Ch4rlie]

Is your nitrite test kit still in date, sometimes test kit get a little unreliable if it’s approaching or past its use by date which you should see at bottom of bottle.

Is there any nitrite coming from your tap water?
Nitrite is less toxic than ammonia so having a reading below 0.25ppm does not duly concerns me much.

I think RCS will cope with this fairly well but of course do a water change as soon as you see nitrite.

And of course as you mentioned plants will help to consume ammonia.

I feel the tank will be fine in terms of bb for shrimps as there is very little bioload coming from shrimp tbh.

Give it some time, watch the shrimps as they’re the ones who will give you tell tale signs to you that’s there’s something up with the tank water not the test kits.

The bb and tank will eventually reach their equilibrium given time.

Do test the tap water just to see if anything comes from that, probably not but one less thing to tick off the list anyway.

 

[AdoraBelle Dearheart]

Is your nitrite test kit still in date, sometimes test kit get a little unreliable if it’s approaching or past its use by date which you should see at bottom of bottle.

Is there any nitrite coming from your tap water?
Nitrite is less toxic than ammonia so having a reading below 0.25ppm does not duly concerns me much.

I think RCS will cope with this fairly well but of course do a water change as soon as you see nitrite.

And of course as you mentioned plants will help to consume ammonia.

I feel the tank will be fine in terms of bb for shrimps as there is very little bioload coming from shrimp tbh.

Give it some time, watch the shrimps as they’re the ones who will give you tell tale signs to you that’s there’s something up with the tank water not the test kits.

The bb and tank will eventually reach their equilibrium given time.

Do test the tap water just to see if anything comes from that, probably not but one less thing to tick off the list anyway.

Thank you!
Test kit should be good, it's the API master test kit, less than a year old and stored in the fish cupboard which is cool, dry and dark, and dates on the bottles are for 2024. It usually gives me accurate results I think, I get different results when I test my tank compared to testing my dad's overstocked tank, so I think it's accurate.

Usually tap water is at zero, but I haven't tested it recently and that could have changed, so will test that next!


One concern I have is that if I remove the guppies and leave only the shrimp, their bioload is so low, I don't know if they'll produce enough ammonia to either cycle the filter, or feed the plants enough to do a planted cycle. I'm even tempted to add a couple more guppies since there's only 3 decently sized ones in there right now. I can test twice daily and water change where needed, but I'm also not wanting to put the shrimp at any risk, and the plants in there are brand new and not established yet. I think the Limnophila sessiliflora is beginning to grow already though, it looks more... plumped out and vibrant than when I planted it. Not a plant I've had before, but I selected it since I read it's a fast grower, along with the sword.

I haven't yet added root tabs or liquid ferts. I want to, to help the plants grow, but it won't affect my cycle parameters, will it? @mbsqw1d?

 

[Ch4rlie]

You can add guppies if you really want to, 3 guppies won’t add a lot of bioload but not really necessary imho. Guppies may have a snack on small shrimps btw!

Root tabs should not effect the cycle, depending which ones you get of course, I recommend the Seachem Flourish tabs, bit more expensive but it’s good and won’t leach anything into water column.

Would hold off liquid ferts for now, Until after cycle or nitrite issues resolved anyway. The plants will be fine without ferts.

Liquid fert COULD have an effect on the cycle, pretty unlikely but you never know.

Also liquid ferts can have an effect on test readings btw, not unheard of.

Not telling you anything here that you probably don’t already know!

 

[Naughts]

It is not unusual to see low levels of nitrite for a few days in an 'instant cycle' having transferred filter media. I usually add some established substrate to boost it for a couple of weeks.
How did you remove the bleach once you cleaned the aquarium? If there were any traces of it left it could have killed the BB on the filter.
I don't think adding more fish will help at this point. It is OK to reduce feeding to every 2-3 days for a while. Do you have any algae covered rocks/ pebbles that could supplement the shrimps diet?
I'm thinking this is a minor blip and will resolve quickly.

 

[AdoraBelle Dearheart]

Not telling you anything here that you probably don’t already know!

No no, not at all! I'm still a beginner really, only been in the hobby myself for a year, so you're helping me a lot!

Honestly I didn't really even have to cycle my first tank, I did a seeded cycle after running an extra filter on my dad's nightmare tank and pinching some media and substrate from that long established tank, it was almost an instant cycle - just needed some nurturing along as it got established.

I feel like I have a good handle on the nitrogen cycle in basic terms; how to cycle a tank using a seeded cycle or fish-in cycle (I wouldn't want to do a fish in cycle, but it crops up a lot on places like this as I'm sure you know all too well!

I'm confident that I can keep on top of tests and water changes until ether the filter or the plants can keep up with the bioload. But I've certainly never added any livestock until ammonia and nitrites were zero, so doing a fish in cycle with shrimp, makes me a bit nervous! I want to learn what's happening, and whether to aim to cycle the filter, or not even worry about the filter doing anything other than mechanical filtration and aeration, since I want it to be a heavily planted tank anyway, and the plants will presumably starve the filter bacteria eventually anyhow.

But I'm a bit confused now as to whether the sponge I'd assumed was packed full of both types of nitrifying bacteria, isn't consuming the nitrite. I could understand if ammonia was being sucked up by plants and giving me zero ammonia readings, but there must be ammonia eating bacteria in there for me to be getting nitrite readings, right? Since plants would take up ammonia, but not produce nitrite?

Wait... I didn't test nitrAte today... it was at about 10ppm last night before water change, and I haven't tested the tapwater for nitrates recently either. But if tapwater nitrates are at zero as I think they are, and I had nitrates, then I must have the second type of bacteria too, right? Man, I think I'm confusing myself even more...

Root tabs should not effect the cycle, depending which ones you get of course, I recommend the Seachem Flourish tabs, bit more expensive but it’s good and won’t leach anything into water column.

Would hold off liquid ferts for now, Until after cycle or nitrite issues resolved anyway. The plants will be fine without ferts.

Liquid fert COULD have an effect on the cycle, pretty unlikely but you never know.

Also liquid ferts can have an effect on test readings btw, not unheard of.

See? I didn't know any of this The liquid fert I have is only tetra plantamin, want to use that up before buying a better one like TNC lite. Can't remember which root tabs I have right now, and I think the Limnophila sessiliflora looks more like a water column feeder, so I probably would have added the liquid fert to try to help the plants grow faster, since I didn't know it could effect water test results.

Sorry, I'm waffling. Basically I was nervous about putting my shrimp into such a clean tank that wasn't established yet, but had to. But I wasn't expecting to have any issues with the cycle on top of that, so wanted some advice and reassurance, thank you for that!

 

[PheonixKingZ]

It is not unusual to see low levels of nitrite for a few days in an 'instant cycle' having transferred filter media. I usually add some established substrate to boost it for a couple of weeks.
How did you remove the bleach once you cleaned the aquarium? If there were any traces of it left it could have killed the BB on the filter.
I don't think adding more fish will help at this point. It is OK to reduce feeding to every 2-3 days for a while. Do you have any algae covered rocks/ pebbles that could supplement the shrimps diet?
I'm thinking this is a minor blip and will resolve quickly.

I concur with @Naughts. Any bleach left in the aquarium would have killed your bb, even if it was just a small amount.

If you have a really sunny windowsill (and a vase) you can put some pebbles in there to collect algae. (For the shrimp)

It may take a few days, but it will give the shrimp sufficient food for the time being.

 

[AdoraBelle Dearheart]

It is not unusual to see low levels of nitrite for a few days in an 'instant cycle' having transferred filter media. I usually add some established substrate to boost it for a couple of weeks.
How did you remove the bleach once you cleaned the aquarium? If there were any traces of it left it could have killed the BB on the filter.
I don't think adding more fish will help at this point. It is OK to reduce feeding to every 2-3 days for a while. Do you have any algae covered rocks/ pebbles that could supplement the shrimps diet?
I'm thinking this is a minor blip and will resolve quickly.

Thank you so much! Do you know why there is often a nitrite reading even with a transferred filter? It just confuses me, especially getting another (even if low) reading less than 24 hours after a 50% water change and the reading being at zero, when the bioload is so low as well. Shrimp being shrimp, I worry about an unstable cycle, you know.

I was very careful with bleach. The filter was still running on my established tank that whole time, and I used a diluted bleach solution on the tank outside to kill any worm eggs (also on buckets, nets, syphons, heaters etc.) Let the tank sit with the bleach for two minutes, then rinsed thoroughly with a hosepipe, then filled and soaked for a few hours in triple doses of declorinator before rinsing again and allowing to air dry. I was trying to be ruthless against worm eggs, but also careful with bleach of course.

After it was airdry, it sat on the cabinet for a long time, until I added rinsed sand and filled on Tuesday, then transferred filter, so it was bone dry.

I don't dare transfer any substrate or plants from my established tanks to the shrimp tank, because both established tanks had the contaminated plants in them. I would try seeding the sponges from one of those filters if it weren't for that too, but I'd rather ride out a cycle than risk contaminating this tank with that pesticide to be honest.

@PheonixKingZ I do have some clean river stones that I can put in some water in a window to grow some algae for them though, so I'll set that up now, thank you! Why didn't I think of that?? I've even suggested someone do that before getting otos the other day. Thank you!

 

[Naughts]

Thank you so much! Do you know why there is often a nitrite reading even with a transferred filter? It just confuses me, especially getting another (even if low) reading less than 24 hours after a 50% water change and the reading being at zero, when the bioload is so low as well. Shrimp being shrimp, I worry about an unstable cycle, you know.

I was very careful with bleach. The filter was still running on my established tank that whole time, and I used a diluted bleach solution on the tank outside to kill any worm eggs (also on buckets, nets, syphons, heaters etc.) Let the tank sit with the bleach for two minutes, then rinsed thoroughly with a hosepipe, then filled and soaked for a few hours in triple doses of declorinator before rinsing again and allowing to air dry. I was trying to be ruthless against worm eggs, but also careful with bleach of course.

After it was airdry, it sat on the cabinet for a long time, until I added rinsed sand and filled on Tuesday, then transferred filter, so it was bone dry.

I don't dare transfer any substrate or plants from my established tanks to the shrimp tank, because both established tanks had the contaminated plants in them. I would try seeding the sponges from one of those filters if it weren't for that too, but I'd rather ride out a cycle than risk contaminating this tank with that pesticide to be honest.

@PheonixKingZ I do have some clean river stones that I can put in some water in a window to grow some algae for them though, so I'll set that up now, thank you! Why didn't I think of that?? I've even suggested someone do that before getting otos the other day. Thank you!

I don't know why the nitrite shows up on an instant cycle, just that it is what I experience. The levels are always low and always disappear within a few days. Like I said, a blip not a crash.

Your bleach cleaning is textbook.

 

[Ch4rlie]

I doubt bleach would kill all of the BB, am sure Adorabelle rinsed everything very, very thoroughly before even putting anything in the tank. And even then I bet the bleach was already diluted when she cleaned everything.

Remember that BB has pretty tough protection armour in its membrane that covers the BB.



The only sure fire way to kill BB is to dry it out completely over at least a week.

BB is tougher than you think.
(When we speak of rinsing filter media this does reduce the number of BB in filter media as not all BB anchors itself real well so they get washed away hence why mini cycles happen as it’s the number of bb)

I would not worry about growing algae for the shrimps. They find food almost anywhere, microfoods on plant surface etc, just chuck in a few flake or pellets of any fish food if you have no shrimp food. They will happily eat that.

Btw, a real nice treat for shrimps is some nice amaranth leaves or mulberry leaves, they love this stuff!

 

[PheonixKingZ]

@PheonixKingZ I do have some clean river stones that I can put in some water in a window to grow some algae for them though, so I'll set that up now, thank you! Why didn't I think of that?? I've even suggested someone do that before getting otos the other day. Thank you

Perfect! You can dose the vase with fertilizers to speed up the process, and if you have an extra lamp, you can put that over the tank. You will have little algae treats in no time!

 

[Naughts]

I doubt bleach would kill all of the BB, am sure Adorabelle rinsed everything very, very thoroughly before even putting anything in the tank. And even then I bet the bleach was already diluted when she cleaned everything.

Remember that BB has pretty tough protection armour in its membrane that covers the BB.



The only sure fire way to kill BB is to dry it out completely over at least a week.

BB is tougher than you think.
(When we speak of rinsing filter media this does reduce the number of BB in filter media as not all BB anchors itself real well so they get washed away hence why mini cycles happen as it’s the number of bb)

Pretty much the same sentiment as post #9.

 

[FishGuest5123]

Was the filter moved from a smaller tank? It may just need to catch up.

 

[PheonixKingZ]

When we speak of rinsing filter media this does reduce the number of BB in filter media as not all BB anchors itself real well so they get washed away hence why mini cycles happen as it’s the number of bb)

Umm... are you sure on that? Beneficial bacteria can survive for 48 hours if it’s damp. 24 hours if you just take it out of the tank.

It is the chlorine (From tap water) that kills the bb, and is not a good idea to do so.

I could be wrong, but that is what all my research has shown me...

 

[AdoraBelle Dearheart]

You can add guppies if you really want to, 3 guppies won’t add a lot of bioload but not really necessary imho. Guppies may have a snack on small shrimps btw!

I think I have weird guppies (or I really do overfeed...possible) they don't seem to eat fry! Or shrimp. I don't doubt they would eat shrimplets if they found a tiny one and were hungry enough to try to catch it, but I had nine adult guppies and a bunch of juvenile guppies in the same tank as the shrimp for months, and the colony kept growing. The only time I saw a guppy bother a shrimp was if the guppy was pecking at the same algae wafer that the shrimp was nomming And the shrimp don't seem scared of them either, they hold their ground!

I tend to raise the guppy fry with the adults though until they get large enough or there are enough of them to transfer to the grow out tank. (need to transfer some now really, but also need to cycle the 12 gallon grow out now... hope there's enough BB in either filter to seed it) so when fry are small, I feed three times a day, twice a day once they're a bit bigger. I aim for little and often, so the adults are also well fed and too lazy to bother hunting fry or shrimplets. Plus the tank had enough hortwort and crypts and things for the littles to hide in.

Now they're in a new tank and it's a little more exposed, I hope the guppies don't eat them. I can move the guppies out again if they show too much interest though. No berried females or super tiny shrimplets right now either, so fingers crossed the plants will have grown in a bit more before tiny ones come along again.

*sob* I miss how my tank looked in that photo! I'd finally got it looking the way I wanted it, and now it's all torn up and a mess. But it'll be worth it in the end. Just won't be entering TOTM for a while...