History of slow losses, 2 sick fish out of 36 - how many to treat with trio?

[Jess]

Stats: 45G planted tank. Last water change was 12/30, 25%. Since then, water parameters have been: pH 6.8, KH 80 ppm, nitrates 25-50 ppm, nitrite 0 ppm, GH to be honest, I'm not sure. It just doesn't show up properly on the test strips (it's faint lavender that doesn't match any of the squares even closely). With the API test it's usually 4-6.

Inhabitants: 6 crossband chocolate gouramis, 18 T. hengeli rasboras, 4 Adolfoi corydoras, 6 habrosus corydoras, 3 Tengah halfbeaks.

Notable history: On 12/11 I noticed that my canister filter wasn't running.  I'm not sure for how long it had been off.  I had previously measured nitrates at 50-100 ppm and was suspicious about it, but didn't connect it to the filter.  I actually noticed it because the rasboras were schooling in the middle of the tank way more, and everyone just seemed to be using more of the middle of the tank.  I felt 50-100 ppm wasn't obscenely high, so I did a 25% water change and left the filter off (I just cleaned it out). 10 days later on 12/21 I again measure nitrates at 100 ppm so I did a 40% water change and I turned the fully-cleaned filter back on. I had by then fished out 2 dead bodies - both gouramis.  Originally I had 13, and they've slowly dropped off; by 12/21 I think I had 8.  I also found I had lost 4 halfbeaks.  I decided that 50-100 ppm nitrates must be too high for my fish, and while I don't fully understand the relationship between the filter and my fish dying, I just knew I needed to go back to filter-on mode.  (Maybe this sounds really stupid...but I've heard from a lot of people that canister filters are probably not necessary in a low-to-medium stocked tank because there's so much bacteria everywhere. I wanted to test the theory in my particular tank.)  

Water parameters went back to normal- pH 6.0, KH 20 ppm, nitrates 25-50 ppm, nitrite 0 ppm.  9 days later on 12/30 I added 1lb of crushed coral (that's 25% of what's recommended...I wanted to go slowly and observe).  I'm trying to grow crypts and having trouble, and I felt that bumping up my KH and pH might help enough without hurting my fish.  That brought me to the parameters at the top of this post. 

Present day problem: Since then, 1-2 more fish have died - always the gouramis.  And I have one rasbora who looks like he has dropsy.  Now, if you look through my post history you'll see these friggin gouramis have always given me problems.  They're crazy sensitive.  I have other Indonesian gouramis that are totally flexible and fine (licorice, samurai) just these are such a mystery.  I really love them though.  The first 12 I got I guess 2 years ago, and I lost a couple after a temperature drop due to a cold spell and then 1-2 randomly during the next year. Since then up until the filter fiasco, they'd been fine.  That said, they arrived to me with cloudy eyes - just about all of them.  I read that's a sign of infection?  Anyway, in October 2022 I got 6 more, bringing my total to 13, because they were really aggressive in smaller numbers.  Everything was going ok until the filter thing. Now I have 6. They died off slowly and mostly I don't find the bodies (I believe I've buried 3 out of 7 lost).  One died a few days ago. I saw him "sulking" in a corner with stress coloring, then a few hours later he was dying, looking terrible and heart-breaking.  I have one that is currently struggling - stress coloring.  The only thing I have noticed, visible in the video in link below, is swelling on one fin and possibly tail.  Yesterday he was flashing that fin against plants.

Here's a link to all (it includes videos and captions)

https://imgur.com/a/s722e2j

The questions:

1. All I have is the Med Trio - Maracyn, IchX, and ParaCleanse.  I have a 10G tank, cycled and ready to go, it has a sponge filter, airline tubing, bolbitis on driftwood which I'll have to find a place for, and one danio who I'll need to move as well.  Are these meds suitable?  Treat all or just one or two?

2. Who (besides the two sick ones) should I treat?  All the gouramis at once?  They are a problem fish; I think it's possible they arrive with latent infections that just got exacerbated by the high nitrates and now possibly by the high pH and KH which they probably dislike.  I'm just not sure...what if I treat the healthy ones and they die?  They've been healthy for 2 yrs so maybe I shouldn't push my luck?

3. What about my other 17 rasboras that show no signs of issues? 

 

Thanks everyone.  Sorry for the long post.  I felt the back story about the filter might be important.  I appreciate your advice!

 

 

 

Edited January 14, 2023 by Jess
spelling

[Colu]

I think most of your deaths were caused by your high nitrates if they were 100ppm that will affect fish's immune system leading to secondary infection he's some of the symptoms of nitrate poisoning are rapid breathing loss of color trouble swimming laying on the bottom of the tank curling head and tail reduce feeding response  what I would get your nitrates down to 20ppm add Indian almond leaves as they have antibacterial and antifungal properties depending on the quality of leaves you will have to add one leaf per gallon to get a benefial effective I would also do a course of maracyn in food just in case there's a bacterial component to the deaths @Jess

[nabokovfan87]

What temperature is the tank?

Related video on the topic.
 

 

Edited January 15, 2023 by nabokovfan87

[Jess]

On 1/14/2023 at 7:05 PM, nabokovfan87 said:

What temperature is the tank?

Oh good call! Temp is 78 degrees and has been stable for at least the last few months.  I use Cory's heater.  Thanks for linking this video - I had seen it before but it was a great reminder to watch it again.

[Jess]

@Colu thanks so much for this advice.  I have catappa leaves from the Co-Op, I'll throw 4-5 in there now.  I think you're right about my problem. It's useful to learn that nitrates have a negative effect on immunity.  The nitrates have been back down to 25 ppm since 12/21 but maybe the period of high nitrates was long enough that it lowered their immunity and that's why I'm just kind of slowly losing them.  They slowly succomb to secondary infections.  That makes sense because what was so frustrating is I could never tell what's going on - any time I saw a sick one, they look a little bit different.  The gouramis only thing they have in common is their stress coloring - as soon as I see it I know in the next 1-2 days he/she will die.  According to my records, my nitrates were high for about two months - I did more frequent water changes but I was struggling with that for awhile and couldn't figure out why they were high.  

I have to order the Seachem Garlic Guard and Focus online; nobody near me carries it in store.  I'll most likely loose these two fish before those arrive but maybe I can save the rest of them.  I think there is nothing else I can do other than keep my stupid filter on and test water frequently to make sure nitrates stay low.

Thanks again for your help!  I didn't think about administering antibiotics in food. That's a good idea.

[Colu]

On 1/15/2023 at 12:53 AM, Jess said:

@Colu thanks so much for this advice.  I have catappa leaves from the Co-Op, I'll throw 4-5 in there now.  I think you're right about my problem. It's useful to learn that nitrates have a negative effect on immunity.  The nitrates have been back down to 25 ppm since 12/21 but maybe the period of high nitrates was long enough that it lowered their immunity and that's why I'm just kind of slowly losing them.  They slowly succomb to secondary infections.  That makes sense because what was so frustrating is I could never tell what's going on - any time I saw a sick one, they look a little bit different.  The gouramis only thing they have in common is their stress coloring - as soon as I see it I know in the next 1-2 days he/she will die.  According to my records, my nitrates were high for about two months - I did more frequent water changes but I was struggling with that for awhile and couldn't figure out why they were high.  

I have to order the Seachem Garlic Guard and Focus online; nobody near me carries it in store.  I'll most likely loose these two fish before those arrive but maybe I can save the rest of them.  I think there is nothing else I can do other than keep my stupid filter on and test water frequently to make sure nitrates stay low.

Thanks again for your help!  I didn't think about administering antibiotics in food. That's a good idea.

You could add some floating plants such as water lettuce Amazonian frogbit or quick growing stem plants like hornwort elodea to help soak up some of your nitrates 

[Jess]

@Colu I have A TON!  Red root floaters and hydrocotyle (that I had added to soak up more nitrates).  I want frogbit but I've never seen it available where I live.   But I remove handfuls of red root floaters every few days.  The filter being off was a huge problem, I guess...still not exactly sure though why that caused nitrates to increase.  More bacteria = more efficient processing of ammonia -> nitrite -> nitrate ... so less bacteria should have meant higher ammonia/nitrite, not higher nitrate.  No?  At that time this tank had very low pH and KH so maybe that had something to do with it.  

[Colu]

On 1/15/2023 at 3:29 AM, Jess said:

@Colu I have A TON!  Red root floaters and hydrocotyle (that I had added to soak up more nitrates).  I want frogbit but I've never seen it available where I live.   But I remove handfuls of red root floaters every few days.  The filter being off was a huge problem, I guess...still not exactly sure though why that caused nitrates to increase.  More bacteria = more efficient processing of ammonia -> nitrite -> nitrate ... so less bacteria should have meant higher ammonia/nitrite, not higher nitrate.  No?  At that time this tank had very low pH and KH so maybe that had something to do with it.  

Very low pH slows down the growth of your benefial bacteria that could have attributed to the raise in nitrates 

Edited January 15, 2023 by Colu