Water Chemistry Confusion - Please HELP!

[Cdelgado]

Population:
1 molly
2 Platies
2 angelfish (1 is dying ?)
2 goldfish (my 90 yr-old dad brought these home; they’ve been doing fine in the tank for a couple of months)
1 pleco (died 2 days ago)
Setup:
75 gallon tank
Fluval 407 Canister filter
Fluval e300 heater
200 watt supplemental heater

I noticed one of my angels had damaged fins. On the advice of the petco folks, I used artemis microbe lift, removing the carbon media from my filter. I dosed according to the bottle for 6 days since I saw improvement. On day 7, I woke up to a dead pleco. I decided I needed to put the carbon back in the filter. Since I was messing with the filter, I figured I’d do a quick clean. I rinsed all the sponges and other media in the tank water that I’d gotten from inside the filter. I rinsed the carbon bags in the tank water and put them back in. I also vacuumed the substrate and did a 30% water change. I used aqua safe according to the directions on the bottle. Next morning one of my angel’s was nose down and barely alive. Other fish in the tank are flashing, swimming weirdly and being unusually aggressive and intermittently laying on the bottom and not moving much. I also noticed one of the goldfish has a white wound under his eye (not sure if it’s fungus or an injury. I tested the water and found nitrates to be slightly up (but in the safe zone) and the ph was 7.4. The kh however was quite low. I treated the water with Tetra easy balance (using the weekly dosing formula of 10/ML per 10 gallons. I’ve done so much research but am not sure if I did the right thing with the easy balance. Should I have used an alkalinity buffer? Or should I try the crushed coral option? Did I do something wrong ending the Artemis treatment and putting the carbon bags back right away? Did my carbon go bad in the 6 days outside the tank? That angel is still hanging on; I hate to see them stressed and suffering. Can you help?

 

[Aiken Drum]

What precisely are your water parameters? If possible, parameters before you did the water change, and after you cleaned the filter.

How long has the tank been set up? What is your normal water change schedule?

Most of the time carbon doesnt do anything. Carbon removes organic compounds. This is usually one of 3 things. Removing medication once a treatment course is ended. Removing tannins released by driftwood which colour the water. Removing phenols which cause smells. Medication is only something periodically. Tannins eventually leech out completely. If you are keeping up with your regular water changes, aquariums shouldnt smell. Unless you are dealing with with a specific issue, carbon wont be doing anything, it needs to be replaced every month or so, and its expensive.

As said carbon needs periodically replacing to function, same as the carbon in your cooker hood. Its sometimes cited that carbon will release everything its absorbed once its used up, but im not sure that its true it does that. But to rule that out, how long has that particular batch of carbon been in your filter?

Fish flashing is usually caused by parasites or poor water quality. When precisely did your fish start to flash?

Plecos (and other scaleless fish) are not known for being tolerant of medication. How long had you had the pleco? Do you have driftwood in the tank for it to munch on? What was you feeding the fish?

 

[Cdelgado]

Thanks so much @Aiken. The tank has been up and running for about 8 months. Not entirely sure what the parameters were before cleaning filter but can give you more detailed numbers on the status now (just got a more detailed test kit besides the easy strips to see if I can learn more.


I was feeding the pleco algae wafers. And not sure if I should replace carbon or not. So confused and very very sad.

 

[Aiken Drum]

In simple terms, carbon is full of microscopic holes that absorb organic compounds. Once these holes are full the carbon becomes ineffective and needs to be replaced. The general consensus is that carbon is used up somewhere between a couple of weeks and a month. It will depend on how much work the carbon has done.

I really dont think the carbon is an issue here. Even if its used up, it will just stop working. And as said its uses are pretty limited and most of the the time on a well maintained tank it wont be doing anything useful.

The likely cause of the flashing is either water quality or parasites. When you get your test kit we can look at the water quality. The pleco dying could easily be a reaction to the medication. This why medicating in a hospital tank is usually a good idea so you arent treating healthy fish who dont need the stress of bring medicated.

There are issues with your choice of fish. Goldfish are temperate (room temperature) and the rest are tropical. Plecos are known for trying to eat goldfishes slimecoat too. But at this stage i dont see that as being your issue.

For now i would up the water changes and keep an eye out for other symptoms until you get your test kit. Take a sample of water before to test later before you do your water change.

 

[Colin_T]

Hi and welcome to the forum

Can you post some pictures and video of the fish and entire tank so we can check them for diseases?
You can upload videos to YouTube, then copy & paste the link here.
If you use a mobile phone to film the fish, hold the phone horizontally so the footage fills the entire screen.

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What are the tank dimensions (length x width x height)?

What is the GH (general hardness), KH (carbonate hardness) and pH of your water supply?
This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

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BASIC FIRST AID FOR FISH
You should also do this if you lose a fish.

Test the water for ammonia, nitrite, nitrate and pH.

Wipe the inside of the glass down with a clean fish sponge. This removes the biofilm on the glass and the biofilm will contain lots of harmful bacteria, fungus, protozoans and various other microscopic life forms.

Do a 75% water change and gravel clean the substrate every day for a week or until the problem is identified. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in. It also removes a lot of the gunk and this means any medication can work on treating the fish instead of being wasted killing the pathogens in the gunk. If you have overdosed or poisoned fish with medication, the big daily water changes will remove the poisonous chemicals.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use the media. Tip the bucket of dirty water on the garden/ lawn. Cleaning the filter means less gunk and cleaner water with fewer pathogens so any medication (if needed) will work more effectively on the fish.

Increase surface turbulence/ aeration to maximise the dissolved oxygen in the water.

 

[Caliban07]

The fish are stressed and stress is one of the largest contributing factors to disease. Not just in fish, humans also. Stress induces the cortisol hormone which is vital for momentary situations but destructive long term. Chronic elevated cortisol levels suppresses immune function which allows pathogens to wreak havoc. The pathogens are always there but healthy fish can limit there effects.

I would personally add an airstone to the tank to allow consistent gas exchange. Turn the flow down or use a spray bar and point this to the surface to alleviate potential stress caused by inescapable areas of high flow.

The pleco is a burden at this point and the wafers will be contributing to deterioration of water quality. Unless the water is toxic i.e elevated ammonia levels, smaller, consistent water changes would be more beneficial that larger ones.

You don’t want to do to much all at once. The fish need stable parameters, and high levels of oxygen.

Try to be consistent but keep the fishes exposure to stressful situations to a minimum.