Feedback on plants, fertilizer, nitrates...

[slowdown]

This is an unheated 20G long that's been running for several years. It has an AquaClear 30 HOB filter and a pre-filter at the intake, plus an airstone. Until last week, it had a dozen white cloud minnows (gold variety) and a half dozen kubotai rasbora.

Typically do a 30-50% WC with a Python weekly, filter half that often or less as numbers dictate - it contains a sponge, biomedia, and an ammonia-filter pad. The substrate is sand and fairly thinly layered. Lights are generally on 8-10 hours/day.

The problem: I had a large algae bloom last month that took a couple weeks to get under control and since then have lost 4 of the minnows; this after losing an entire school of Cories about a month ago. The rasbora seem fine.

I tested the water 3 days ago and was shocked to see the nitrates at 80 (at least - very dark red, hard to say exactly; API liquid test kit). Ammonia was .25 (presumably from a recently dead fish, since removed) and nitrites 0. Did a 50% WC 3 days ago and another today - nitrates are down to around 30-40. PH has been steady at 6-6.5 forever; we are on soft municipal water and I typically keep soft-water fish.

Tap water nitrates are 0 (tested 3 days ago).

The only changes in the tank are these:

-I'd started using EasyGreen per bottle instructions once every week or two 

-After WC's didn't help with the algae growth (green algae), I left the lights off for 3 days last week.

The banana plant leaves look yellowish and droopy and the sword leaves have holes like a potassium deficiency; the grass-like plants (not sure what they are) were thriving until the algae bloom and now are struggling. 

I've attached a photo of the tank (a couple plants got loose during the WC) and one of one of the fish that died. Any suggestions? Would more plants help the nitrate levels stay low (have to be cat-friendly)? I can keep doing WC's to get nitrates down now, but I don't want this to happen again. I've stopped dosing the Easy Green because of the high nitrates, but thinking that isn't a good long-term option for the health of the plants - but I also don't want to kill the fish. Is there something else I'm not thinking of?

 

[JE47]

I will tag @Colu for the sickness portion of this thread and @JoeQ for the plant portion. Hopefully they can lend you some aid.

[JoeQ]

The problem you are most likely facing is without Phosphates and Potassium (added from EZ Green dosing) your plants are refusing to eat.  If it were me (and I had no other fertilizer options) id resume dosing ez green and try to get your plants eating again. Along with a few additional water changes you should see your nitrates level off.

[Colu]

Looking at the redness to belly I would be learning to wards a bacterial infection a little more information would be helpful have you added any new fish recently have you notice any rapid breathing hanging out near the surface lethargy 

[slowdown]

On 11/30/2023 at 6:32 AM, Colu said:

Looking at the redness to belly I would be learning to wards a bacterial infection a little more information would be helpful have you added any new fish recently have you notice any rapid breathing hanging out near the surface lethargy 

I haven't added any new fish for a couple of months. The fish in the photo was hanging out near the top and appeared to have buoyancy problems - I thought it was swim bladder but it went from first sign of distress to death in hours. The other three were at the bottom and likewise, went quickly - lethargy for one, the others I just found dead - but all three at the bottom, without bloating, but with the same red splotches either on the belly or behind the gills. The only changes I'd made were to keep the lights off to try to kill off the algae and the Easy Green that seemed to spike the nitrates - though it's possible that the nitrates were already high. I'm very good about regularly checking ammonia - less good about nitrates (lesson learned) - but also not sure why nitrates would be that high with regular water changes.

The only other really odd thing with this tank is that I used to have a group of false Julii Cories in the tank and some months ago, all but one died - the remaining one is fat and happy, though solo. I've tried adding more to it twice over the past year so he wasn't alone (once last summer spring, again earlier this fall) and both times all died quickly, other than this one. It's possible the Easy Green/nitrates have nothing to do with the fish death - just was stumped as to other options.

On 11/30/2023 at 5:51 AM, JoeQ said:

The problem you are most likely facing is without Phosphates and Potassium (added from EZ Green dosing) your plants are refusing to eat.  If it were me (and I had no other fertilizer options) id resume dosing ez green and try to get your plants eating again. Along with a few additional water changes you should see your nitrates level off.

Is that the best fertilizer option for this situation, or should I be using something else? If EasyGreen, is the bottle dosing (1 pump/10g weekly) appropriate? If I'm doing more frequent, but smaller, water changes, do I still just dose weekly with the fertilizer? The plants are definitely suffering. I'm not sure what created the algae bloom in the first place but it was pretty severe and the plants started going downhill when that happened.

[JoeQ]

On 11/30/2023 at 8:55 AM, slowdown said:

Is that the best fertilizer option for this situation, or should I be using something else? If EasyGreen, is the bottle dosing (1 pump/10g weekly) appropriate? If I'm doing more frequent, but smaller, water changes, do I still just dose weekly with the fertilizer? The plants are definitely suffering. I'm not sure what created the algae bloom in the first place but it was pretty severe and the plants started going downhill when that happened.

Ideally the best option would be to dose Phosphates and Potassium for a week (or so) but then you would most likely run into other deficiencies, so you would want to restart dosing EZ Green relatively soon. IMO spending money for a few doses of fertilizer isn't a great idea but it's your money. Who am I to tell you how to spend it! 

As far as your dose, Algae can also be encouraged by under dosing ferts. You have some nice growth going, was 1 pump a week always your dose? If so I believe under-dosing might have been how the algae got a foothold. As your plant mass grows so should your dosage. 

Edited November 30, 2023 by JoeQ

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On 11/30/2023 at 9:14 AM, JoeQ said:

Ideally the best option would be to dose Phosphates and Potassium for a week (or so) but then you would most likely run into other deficiencies, so you would want to restart dosing EZ Green relatively soon. IMO spending money for a few doses of fertilizer isn't a great idea but it's your money. Who am I to tell you how to spend it! 

As far as your dose, Algae can also be encouraged by under dosing ferts. You have some nice growth going, was 1 pump a week always your dose? If so I believe under-dosing might have been how the algae got a foothold. As your plant mass grows so should your dosage. 

Fully agree on not spending for such short-term use.

I was dosing 2 pumps at a time - but not consistently every week. So under-dosing could certainly make sense. How do you control nitrates while also giving plants the fertilizer they need? I can do more frequent water changes, but won't that just remove the nutrients I'm putting in?

[JoeQ]

On 11/30/2023 at 10:36 AM, slowdown said:

Fully agree on not spending for such short-term use.

I was dosing 2 pumps at a time - but not consistently every week. So under-dosing could certainly make sense. How do you control nitrates while also giving plants the fertilizer they need? I can do more frequent water changes, but won't that just remove the nutrients I'm putting in?

Healthy plant growth will remove nitrates, more healthy plants (especially fast growing floating plants) will remove a lot of nitrates!!!

The idea of water changes in a planted tank isn't so much about removing nitrates. It is more about resetting the nutrient balance. An imbalance of nutrients will also cause algae on account of too much of nutrient X and not enough Y will cause poor growth.

Edited November 30, 2023 by JoeQ

[slowdown]

On 11/30/2023 at 10:45 AM, JoeQ said:

Healthy plant growth will remove nitrates, more healthy plants (especially fast growing floating plants) will remove a lot of nitrates!!!

The idea of water changes in a planted tank isn't so much about removing nitrates. It is more about resetting the nutrient balance. An imbalance of nutrients will also cause algae on account of too much of nutrient X and not enough Y will cause poor growth.

Thank you for your replies - I'm learning a lot. I've had fish for a long time but the planted part is something I did without knowing much beforehand - and now I'm realizing how much I don't know.

Are there (cat-safe) plants you'd recommend I add? And when you say the water changes are to reset the nutrient balance, how do you know frequency/amount of water to change - what are you testing to determine what is or isn't out of balance? 

[Colu]

With what your describing Redding to the body and Gill's that could be caused by ammonia burn or a bacterial infection as your ammonia reading is at the  low end I  would do I course of maracyn2 in food feeding a small amount twice a day for 7 days just in case there's a bacterial component @slowdown

[JoeQ]

On 11/30/2023 at 11:54 AM, slowdown said:

Thank you for your replies - I'm learning a lot. I've had fish for a long time but the planted part is something I did without knowing much beforehand - and now I'm realizing how much I don't know.

Are there (cat-safe) plants you'd recommend I add? And when you say the water changes are to reset the nutrient balance, how do you know frequency/amount of water to change - what are you testing to determine what is or isn't out of balance? 

I'm not sure what you mean by 'cat safe' aquarium plants. Unless little snowball (imaginary cat name) is swimming laps in your tank I don't see an issue! 😂

As for how to guage when to change water I go by how im dosing. In my main tank im dosing the Estimated Index method, which is basically flooding the system with an abundance of nutrients (macros one day, micros the next) then at the end of the week it is recommended to do a large (50%) water change along with GH booster.

For my 10g tank im doing a poor mans dosing which supposedly is dosing a leaner dose of macros & micros when the lights turn out. Then using a tds meter to guage the need for a water change.

My 15g has a immature eco system so im dosing dry Phosphate, Potassium & dry macros when I don't need Nitrogen; easy green if I do need Nitrogen. Ideally id water change this tank whenever my nitrates/nitrites get over a certain amount.

Now, realistically I already have my equipment out on Sunday soooo all three tanks get a 50% water change!!! Sometimes my 15g gets a midweek change!!! 😂😂😂

That was a lot of words to say it's really at your discretion, but I thought the visual would really drive the point home!!!!!

[nabokovfan87]

You have a very, very thin layer of substrate and it's going to be an issue where the plants can't anchor themselves and build good root structures.  I would have 2.5" minimum thickness for the substrate in a planted tank.  For most situations, the recommendation is about 4" of substrate.
 

On 11/30/2023 at 10:48 AM, Colu said:

With what your describing Redding to the body and Gill's that could be caused by ammonia burn or a bacterial infection as your ammonia reading is at the  low end I  would do I course of maracyn2 in food feeding a small amount twice a day for 7 days just in case there's a bacterial component @slowdown

Adding some salt also helps with ammonia burn!

 

 

On 11/29/2023 at 6:08 PM, slowdown said:

I would move all of your val to the back area of the tank.  I think it's a lily, I would move that towards the front left corner (off-center from the light).  I would try to plant some of the floating stems you have and at least give yourself a chance for those plants to grow without blocking out all of the top of the tank.  Right now you can see it's blocking out the two plants on each end of the tank.

Scrape the glass, all sides, as long as you're seeing this dense algae right now.  Once you get things under control a little bit more and the plants are growing you can then proceed with only scraping the front + sides (if you wish to scrape the sides).

I would also go with a 50% or 75% dose of ferts right now as it's clear you have too much in the water right now and the plants are struggling.

Welcome to the forums @slowdown !

[slowdown]

On 11/30/2023 at 3:14 PM, nabokovfan87 said:

You have a very, very thin layer of substrate and it's going to be an issue where the plants can't anchor themselves and build good root structures.  I would have 2.5" minimum thickness for the substrate in a planted tank.  For most situations, the recommendation is about 4" of substrate.
 

Adding some salt also helps with ammonia burn!

 

 

I would move all of your val to the back area of the tank.  I think it's a lily, I would move that towards the front left corner (off-center from the light).  I would try to plant some of the floating stems you have and at least give yourself a chance for those plants to grow without blocking out all of the top of the tank.  Right now you can see it's blocking out the two plants on each end of the tank.

Scrape the glass, all sides, as long as you're seeing this dense algae right now.  Once you get things under control a little bit more and the plants are growing you can then proceed with only scraping the front + sides (if you wish to scrape the sides).

I would also go with a 50% or 75% dose of ferts right now as it's clear you have too much in the water right now and the plants are struggling.

Welcome to the forums @slowdown !

This is such super helpful, specific information - thank you! I'll add more substrate tomorrow and will scrape and move plants as you suggested. Ammonia is 0 so ok for now - I suspected ammonia burn at first, too.