Fish Die with every water change

[Winterfoot]

So I'm a little stumped and looking for guidance.

 

I have a 7 gallon cylindrical tank, planted heavily with several plants (all slow growing which was a mistake.) I inject Co2, have a fluval plant 3.0 nano light run 8 hours a day. and an oase thermo filter. temp is maintained at 74-75F. I can provide plant species if neccessary. substrate is ADA amazonia, with ADA power sand as a sub layer.

For stock, I've got 2 siamese flying foxes (one now...), 2 cardinal tetras, 2 otocinlus, and maybe 10 amano shrimp. 

Water parameters are stable, and I've not observed any spikes in any category. I measure pH, hardness, ammonia, nitrate, nitrite, temp, phosphate, TDS, CaO, and MgO. 

last recordings were as follows:

Temp: 75

pH: 6.6

Ammonia: 0.25

Nitrite: 0

Nitrate: 0

Phosphate: 0.5

Calcium: 50

MgO: 50

TDS: 403

 

I fetrilize with Easy green, 1ml every 4 days, 1ml of Fe2O3 every seven days, and recently have had to treat staghorn algae blooms with flourish excel.

 

The problem is, every time I do any level of water change, the fish will become unbalanced, swim upside down, and die. one or two shrimp will go as well. Curious behavior is they will all swim to the top of the tank as if they need O2, so I will adjust my return line to be above the water line aerate the water column, but it makes no difference. It happens with any % water change I've done. Though this last change, the behavior was delayed almost 24 hours. The shrimp will all also crowd at the top of a branch I'm got in the wood.

I was thinking there was a temperature differential in the water change water, so I tested and got it within 1F of itself before adding the water. This still caused some death. 

I should note, water change is done in 800ml intervals with 1ml of dechlorinater and 1-2 drops of stress reliever. 

any insight would be super helpful cause I am stumped.

[Cory]

I'd question, why are we changing water? It would seem that the tank is looking for more nutrients, thus we are dosing ferts, what are we removing with the water change? Each time you change water, you'll be changing the pH as well as the oxygen level. Dechlorinators reduce oxygen in the way they work. Being that this is a small system of 7 gallons, one of the crux of the nano tank is how unstable they can be.

If it were my tank, I'd get the pH to 7.0 at the minimum. Thus when the co2 was on it wouldn't push it too low. I'd relax water changes to probably once every 60 days or so.  From there I'd observe and dial in if I actually need to dose ferts, without knowing the plants it's hard to say, but ada soil is quite potent if it's new still.

[Andy's Fish Den]

I would cut back on water changes, and with only a 7 gallon tank, the stocking level might be a little high, which could be the reason you are having ammonia, along with using the ADA Amazonia which will also give off ammonia when it is new. You shouldn't have to dose that much fertilizer with using the ADA soil unless it is old and getting depleted. You want to have ~20ppm nitrate in the water, which you aren't accomplishing by doing the water changes. Have you tested your source water? If you have city water, they could be treating with chloramines, which could be part of the problem. 

I would cut back water changes, test water to make sure the nitrogen cycle is taking care of the ammonia and you are ending up with nitrates

Just saw @Coryreplioed and said basically same thing I was typing out. 

[Socqua]

Listen to Cory, I'll just add that you want to get that ammonia to 0. Do you have it in your tap? Because I'm surprised you have any readings unless you're tank isn't cycled or it's from the soil. I would think the plants would help remove it too.

Edited February 11, 2021 by Socqua

[Brandy]

16 minutes ago, Winterfoot said:

I fetrilize with Easy green, 1ml every 4 days, 1ml of Fe2O3 every seven days, and recently have had to treat staghorn algae blooms with flourish excel.

 

The problem is, every time I do any level of water change, the fish will become unbalanced, swim upside down, and die. one or two shrimp will go as well. Curious behavior is they will all swim to the top of the tank as if they need O2, so I will adjust my return line to be above the water line aerate the water column, but it makes no difference. It happens with any % water change I've done. Though this last change, the behavior was delayed almost 24 hours. The shrimp will all also crowd at the top of a branch I'm got in the wood.

I was thinking there was a temperature differential in the water change water, so I tested and got it within 1F of itself before adding the water. This still caused some death. 

I should note, water change is done in 800ml intervals with 1ml of dechlorinater and 1-2 drops of stress reliever. 

any insight would be super helpful cause I am stumped.

You are having symptoms similar to what I have seen...when I have dosed dechlor and excel too close to each other. Stop using excel, and try a water change with the minimum amount of dechlor you can use--treat just the water before you add it. I bet you see an immediate reduction of symptoms and no more losses.

[JaredL]

I would ask how you are measuring the amount of co2 you have in the water. Drop checker? Kh to Ph ratio chart? What is your Kh? With a ph of 6.6, I would be concerned if your Kh is over 3dkh(~54ppm I believe) as this could indicate dangerous levels of co2. You mentioned your fish looking like they were gasping for O2, so that's what leads me to key in on your co2 levels.

I would also add that since you are injecting co2, your ph can vary from right before you turn it on to right before you turn it off. Sorry if I'm telling you things you already know.

Edited February 11, 2021 by JaredL

[Coronal Mass Ejection Carl]

Excel is the primary suspect. It's fish poison, after all.

[Mmiller2001]

Sounds like you are pushing the boundaries of CO2 for your current stock. Often, tap water has higher ppm CO2 due to all the things the city does to the water. You might be at that boundary, and your water reserve is pushing beyond the ppm they can handle. I would plan your water changes 24 hours in advance. That means, fill your buckets, dechlorinate immediately and drop an air stone or pump in the bucket/s. Wait 24 hours before using that water for your change. Do your water changes before CO2 starts or after it stops. Ignore pH differences from bucket to tank. pH swings do not harm fish, that is BS regurgitated from early days when "things" were less understood. Test tank KH and reserve KH. If they are within 1.5dKH from each other, you're good to go. Osmotic swing is what kills fish. Example: my tank pH 7.4, CO2 lowers pH to 6.2. My water change reservoir is pH 9.2, but my KH matches my tank.

1. Age your water change reserve with stone or pump.

2. Increase filter turnover to 5x to 10x water volume per hour.

3. Add faster growing plants: stem plants (Pennywort, Moneywort, Ludwigia ect) Use that good substrate!

4. Start surface skimming! You are high tech! Go high tech!! CO2 and O2 are independent, have lots of surface agitation.

5. Dump Easy Green, you are high tech! EG is great low tech, but way too expensive. Go dry firtz, way way cheaper and control.

6. Plan for the future, tap water is unpredictable. Start thinking about upgrading to RO/DI if you stay high tech.

Edited February 11, 2021 by Mmiller2001

[Winterfoot]

Hi guys,

I'm blown away by the level of detail, and the promptness of response.

Corey, thanks. I'm long time listener, first time caller so to speak. I was wondering myself why I change water since my last tank I got to a point where it was so heavily planted and stable that I went 6-7 months without a water change. This is a newer tank, so I wanted to make sure that it had time to stabalize before attempting that again. Granted the old tank was a 75 gallon as opposed to my desktop 7 gallon. My plants include: Anubias nana petite, taxiphyllum barberi, rotala nanjenshen, alteranthera reineckii "mini",and ulrticala graminifolia. They're all slow growers as the thought process was avoid constant pruning, but I realize they may not be taking up the nutrients as fast as they should as indicated by a high TDS reading. I'll cut the ferts, as the tank is roughly 2 months old. Should I also stop the CO2? the plants and algae blooms seemed to slow down their rate of growth when I introduced and it seemed to have no adverse effect on the fish as this issue happened both prior to and after the introduction thereof. Incoming customer reviews once I can sit and focus!

 

For Andy and MMiller, My city water is touted as one of the cleanest in the US. Besides that point since I don't tend to trust what officials tell me, I have a whole home water filtration system which targets heavy metals, particulate, adds in a softener (I believe I need to check), as well as UV sterilization. I installed in on a bypass loop so I can switch it on and off at a whim. The system should also be removing chloramines as well, so I wonder if I overdo it with the dechlorinator.

for Brandy, I'm only using the excel to spot treat the staghorn as it went wild. the nano 3.0 was too bright and too long when I first set it up. Once its cleared up I don't plan on using it. Althought today I may try to hunt down a Siamese algae eater. If identified properly it should eat the staghorn (according to the internet anyways).

 

Jared: I'm not doing any calculations on my CO2 for accuracy, I'm using the drop checker with the color changing fluid. I keep it in the green, though once or twice I've forgotten to turn it on and dipped to the blue. I'm just using an old fluval co2 injection updated with some better tubing and glassware. The cost of a proper system for co2 with a timed solenoid is kind of excessive in my mind for a 7 gallon, but I may need to go automation. As previously mentioned, the fish died in this manner both before and after introduction of CO2 so my gut is that it's not related. Can you send a good website/explanation of those calculations? Anything that gives better knowledge, or control in my mind is good.

 

MMiller, I like the gradual nature and aging process. I use something similar in my work. (Materials engineering) I'll adopt some of those processes. What product do you reccomend for surface skimming? Do you have more resources on education in that manner? Easy Green worked pretty well in my old large tank, I had reserve stock. Since the current tank is 7 gallons, the cost is nominal. I'm only using 1ml of it every 4 days. I do need to dig into the chemistries of other ferts on the market, and compare to what my plants require. Often I think of these chemical additives as situational. It's been a good product prior, but I had different plants at that point.

 

[Mmiller2001]

4 minutes ago, Winterfoot said:

Hi guys,

I'm blown away by the level of detail, and the promptness of response.

Corey, thanks. I'm long time listener, first time caller so to speak. I was wondering myself why I change water since my last tank I got to a point where it was so heavily planted and stable that I went 6-7 months without a water change. This is a newer tank, so I wanted to make sure that it had time to stabalize before attempting that again. Granted the old tank was a 75 gallon as opposed to my desktop 7 gallon. My plants include: Anubias nana petite, taxiphyllum barberi, rotala nanjenshen, alteranthera reineckii "mini",and ulrticala graminifolia. They're all slow growers as the thought process was avoid constant pruning, but I realize they may not be taking up the nutrients as fast as they should as indicated by a high TDS reading. I'll cut the ferts, as the tank is roughly 2 months old. Should I also stop the CO2? the plants and algae blooms seemed to slow down their rate of growth when I introduced and it seemed to have no adverse effect on the fish as this issue happened both prior to and after the introduction thereof. Incoming customer reviews once I can sit and focus!

 

For Andy and MMiller, My city water is touted as one of the cleanest in the US. Besides that point since I don't tend to trust what officials tell me, I have a whole home water filtration system which targets heavy metals, particulate, adds in a softener (I believe I need to check), as well as UV sterilization. I installed in on a bypass loop so I can switch it on and off at a whim. The system should also be removing chloramines as well, so I wonder if I overdo it with the dechlorinator.

for Brandy, I'm only using the excel to spot treat the staghorn as it went wild. the nano 3.0 was too bright and too long when I first set it up. Once its cleared up I don't plan on using it. Althought today I may try to hunt down a Siamese algae eater. If identified properly it should eat the staghorn (according to the internet anyways).

 

Jared: I'm not doing any calculations on my CO2 for accuracy, I'm using the drop checker with the color changing fluid. I keep it in the green, though once or twice I've forgotten to turn it on and dipped to the blue. I'm just using an old fluval co2 injection updated with some better tubing and glassware. The cost of a proper system for co2 with a timed solenoid is kind of excessive in my mind for a 7 gallon, but I may need to go automation. As previously mentioned, the fish died in this manner both before and after introduction of CO2 so my gut is that it's not related. Can you send a good website/explanation of those calculations? Anything that gives better knowledge, or control in my mind is good.

 

MMiller, I like the gradual nature and aging process. I use something similar in my work. (Materials engineering) I'll adopt some of those processes. What product do you reccomend for surface skimming? Do you have more resources on education in that manner? Easy Green worked pretty well in my old large tank, I had reserve stock. Since the current tank is 7 gallons, the cost is nominal. I'm only using 1ml of it every 4 days. I do need to dig into the chemistries of other ferts on the market, and compare to what my plants require. Often I think of these chemical additives as situational. It's been a good product prior, but I had different plants at that point.

 

This guy knows what he's talking about. He's also on youtube. Look for the learn section in the drop down.

https://www.2hraquarist.com/

[Mmiller2001]

Are you using water before or after your filtration system?

[Winterfoot]

I'm adding the water direct into the tank, but it's tall and narrow so it should move fairly quickly through it. 

I'm kicking myself a bit as I think I have some spots with little to no flow which I don't want to try and fit a power head in there.