Tank Tests OK But Something Not Right?

[TheGunzel]

Hello all,

I’m after some advice about my tank set up because I suspect something isn’t quite right.

I have an Aqua One 127 litre tank which was given to me by someone who couldn’t keep it any more. Prior to that I didn't have any experience keeping fish so I've been trying to educate myself since then.

The tank seemed to be cycled when I received it (that was about 12 months ago) but about 6 months ago it crashed and while the water testing results were OK the water wasn’t nice and clear. I only had some neon tetras in the tank and they survived but I suspect the water cloudiness at the time was high ammonia.

Eventually the tank cycled and the water quality improved but my issue now is that unfortunately I’ve had 3 corydoras and 1 neon tetra die in the last few weeks so something must be wrong but I can’t figure out what it is.

I’ve put a sponge filter in the tank because I was advised that it would provide another place for bacteria to grow other than the tank filter cartridges.

I’ll detail my maintenance regime and my latest water test results:

• I do a water change of 30% about once a fortnight
• Each time I do a water change I also vacuum the gravel
• The filter cartridges I leave in place and also the sponge filter in the tank itself
• The ornaments are taken out and scrubbed with either hot tap water, or, if they have quite a bit of algae on them, a weak solution of vinegar and hot water and then rinsed thoroughly
• After each water change I add a capful of Stability and also some API Tap Water Conditioner

For my water testing I use an API Freshwater Master test kit.

The results of my last test a few days ago were as follows:

• PH – 6.4
• High Range PH – 7.4
• Ammonia – 0ppm
• Nitrite – 0ppm
• Nitrate – 10ppm
• Water temp. – 26 degrees Celsius

I’ve also tried some API Stress Coat because someone who had a look at one of the sick Corydoras remarked that its skin didn’t look right (they work in a pet shop and have had a bit to do with fish) and that was what they suggested I try.

The tank water looks good, it seems to be testing OK from what I’ve read and the fish in there seem to be eating well and are quite active so I I’m looking for some feedback or suggestions on what I could be doing wrong.

I’ve attached a pic of my aquarium.

I’ve been told the Corydoras like to be in a group of 3 or 4 but I don’t want to add any more fish at all until I know what could be the problem.

Thanks in advance.

 

[Oblio]

Welcome to TFF!
Not exactly sure what is wrong but noticed a few things.

If your tank is cycled, all you need to add is API Water Conditioner at WCs
Stress Coat is generally not recommended as it (IIRC) contains Aloe Vera. Less is more when it comes to adding chemicals to your tank.
If your pH is not at the highest measurement on the API Normal Range test, you don't need to use the High Range test.
Do you know your GH and KH hardness?, this is useful to determine best species to keep.
You didn't state the Corydoras species, but your temp (26 C) seems a tad high, depending on the species, also a bit high for Neons.

seriouslyfish.com is a good reference site

Paracheirodon innesi – Neon Tetra (Hyphessobrycon innesi, Cheirodon innesi) — Seriously Fish

www.seriouslyfish.com

 

[Colin_T]

Hi and welcome to the forum

Any pictures of the dead fish, or a description of what they looked like when they died, (ie: anything different on them, red marks, white bumps, missing fins, etc)?

Pictures of the remaining live fish?

Did you add anything or do anything to the tank in the 2 weeks before you started losing fish?

When you do the water changes, do you use buckets that are specifically for the fish, or any bucket around the house?
If you have specific fish buckets, does anyone use them for anything else?

Do you dechlorinate the new water before adding it to the tank?

How often and how do you clean the filter?

Do you have any creams, perfume, hand sanitiser residue, oil, grease or anything else on your hands when you feed the fish or work in the tank?

Does anyone smoke, paint or use any type of aerosol spray in the room with the fish tank?

-------------------
Don't use hot water to clean things for the aquarium. Plastics can leach toxins when heated up under hot water and can poison fish. Just use cold water and a toothbrush or something to scrub it down. Vinegar can also be used and rinse well before putting the item back in the tank.

-------------------
Once a tank is cycled you don't need to keep adding stability all the time. You use it to get the filters going, then either add the remaining contents to the tank or put it in the fridge and use it on another tank.

-------------------
You want to dechlorinate new tap water before adding it to the aquarium. This stops chlorine/ chloramine from getting into the aquarium and potentially poisoning the fish. Just fill a clean bucket with tap water and add enough dechlorinator to treat that bucket of water. Aerate the water and dechlorinator for at least 5 (preferably 30) minutes before adding it to the tank.

If you make the water up before doing a water change, it can aerate while you clean and drain the tank. Then just add the dechlorinated water to the aquarium.

-------------------
If you add some floating plants to the tank, it will make the fish feel more secure. Water Sprite (Ceratopteris thalictroides/ cornuta) is one of the better floating plants. It can also be planted in the gravel if it grows too fast on the surface.

 

[TheGunzel]

Hello Oblio and Colin, thank you both for your replies.

Oblio, I don't know what my GH and KH values are (I had to look up what they were first!) so I guess I better find that out. It seems that I can buy test strips for that?

As for the water temp, from a bit of research a good range for the Neons is 21-27 degrees Celsius and 21-22 degrees Celsius for the Corydoras? I'm not sure what species the albino Cory that I still have is so I've attached a pic.

I've tweaked the heater down a little today so I'll continue adjusting that to lower the water temperature.

Colin,

Attached are some pics of the other Corydoras before they died.

Apologies for the picture quality.

I'll endeavour to get some decent pics of the Neons, they've just been fed and they're too busy for me to get a good picture.

I'll go through the rest of your questions in order.

• No real changes that I can think of in the period of time before the fish started dying. After the first Corydora died I did a water test, the results were pretty much the same as the test results I posted above.
• I have specific buckets for the water change and they're not used for anything else.
• No, I don't dechlorinate the water before I add it to the tank but I have been adding the AP Water Conditioner to the tank directly once I've added the new water. The info you've written about that suggests I should be doing it before. I'll start doing that from now on. What do you use to aerate the water in the buckets? Can I put an air line from a spare bubbler compressor I have into the bucket?
• I was cleaning the filter pads each time I was changing the water. When I say cleaning what I was doing was putting the filter pad into a bucket of tank water and giving it a swirl around and rubbing the cloth face of it to get the green goo off. I haven't done that for a few months because my thinking was that I would disturb the beneficial bacteria in the pads, is that incorrect? I inspect them and was going to wait until they were visibly gunked up before cleaning them.
• I'm pretty particular about making sure my hands are clean and well rinsed before I put them anywhere near the tank. That includes when I feed the fish as well.
• No smoke, paint or aerosols around the tank. I've become that paranoid that I go into the next room to put glass cleaner onto some paper towel to clean the outside of the aquarium.
• I'll stop using hot water to clean the ornaments. Do you have any particular method for removing algae from ornaments? I'm finding the green algae hard to get off and that's using a reasonably stiff bristled brush.

Thank you both again for your replies and advice, it's much appreciated.

 

[Oblio]

No, I don't dechlorinate the water before I add it to the tank but I have been adding the AP Water Conditioner to the tank directly once I've added the new water. The info you've written about that suggests I should be doing it before. I'll start doing that from now on. What do you use to aerate the water in the buckets? Can I put an air line from a spare bubbler compressor I have into the bucket?

Dechlorinate water before you add it. If in a bucket, add to bucket and aerate or mix first, let sit ~ 30 min. You can use a air stone attached to an airline, use a powerhead or pump, or in a pinch stir by hand every 5 minutes. If adding water by hose, add dechlor to tank first then add water from tap to tank. In small tanks, add water slowly so water has a chance to dechlorinate as new water is added. With a small tank it is better to dechlorinate in a bucket, wait 20-30 min then add (pour or pump) to your tank. With a large tank, at normal flow rates, you will never have much chlorine/chloramine as a % of total volume in the tank before it is neutralized. If it takes about 30 min to fill your tank (regardless of the size) you will be fine.

 

[Colin_T]

Yes you can use a spare airline from the tank or air pump to aerate tap water and dechlorinator.

-------------------
Filters should be cleaned at least once a month. Every week or every couple of weeks is fine if the filter is established and more than 2 months old. To clean the filter just squeeze the filter materials/ media out in a bucket of aquarium and re-se the media. Tip the bucklet of dirty water on the lawn.

If you have filter pads, they eventually start to break down and fall apart. You can replace them with sponges for other brands of filters. Just find a filter sponge that is slightly bigger than the filter pad and use a pair of scissors to cut it to size. Sponges get cleaned in a bucket of tank water just like other types of filter media. If you have space in the filter, you can add sponge now so it will have some bacteria when the filter pad/s need to be replaced. Just replace one pad at a time and wait at least a month before replacing any other filter pads.

-------------------
You can bleach plastic or glass ornaments with household bleach. Just leave the ornament in a small container of bleach and water, then rinse the item off really well under tap water and let it dry in the sun for a day. When it no longer smells of bleach, give it another rinse under tap water and put it in the tank.

Some ceramic ornaments have pores in the base and bleach can enter these pores and leach out slowly so try to avoid bleaching ceramics.

The colour on some ornaments is not fixed and bleach can cause it to fade. So if you have a nicely coloured ornament, maybe avoid bleaching it.

*NB* If you use bleach, try to use it outside or where there is very good airflow. Do not use bleach in a closed room with no airflow.

*NB* Wear safety glasses and rubber gloves, and if possible a plastic apron when using/ handling bleach.

-------------------
Regarding the fish, it could be alkalosis, acidosis or gas bubble disease. I've seen it before but can't remember what it is and I no longer have access to my books or notes on my computer because it died a few months ago with all the data on it.

The white slimy stuff on the fish is excess mucous.

The eyes on the bronze Corydoras are sticking out a bit, which suggests some pressure build up in the skull.

I think the bubbles on the skin are from alkalosis or gas bubble disease (a bit like nitrogen bubbles in divers causing the bends).

----------
What sort of filter is on the tank?
Does it have hoses and connectors?
If yes, are these well connected or do they leak a little bit and let air get drawn in?

Do you add anything to change the pH of the tank water?

Do you check the pH of the tap water and aquarium water?
You should check the pH before water changes to make sure the water company hasn't done something weird to the water. If there is a big change in pH between the aquarium water and the tap water, it can cause acidosis (where the pH drops suddenly) or alkalosis (where the pH goes up suddenly). The same thing can happen if you add pH buffering solutions to an aquarium. If you change the pH too much too quickly, you can cause acidosis or alkalosis.

Do you have any wooden airstones or airstones of any type in the tank?

Do you have a power head in the tank that sucks air into the water?

 

[TheGunzel]

Dechlorinate water before you add it. If in a bucket, add to bucket and aerate or mix first, let sit ~ 30 min. You can use a air stone attached to an airline, use a powerhead or pump, or in a pinch stir by hand every 5 minutes. If adding water by hose, add dechlor to tank first then add water from tap to tank. In small tanks, add water slowly so water has a chance to dechlorinate as new water is added. With a small tank it is better to dechlorinate in a bucket, wait 20-30 min then add (pour or pump) to your tank. With a large tank, at normal flow rates, you will never have much chlorine/chloramine as a % of total volume in the tank before it is neutralized. If it takes about 30 min to fill your tank (regardless of the size) you will be fine.

I use a 20 litre bucket for the new water so I'll get another one and have them both filled and treated beforehand and then I can do the whole change at once. I've got a spare air compressor so I'll use that to aerate the buckets.
Using a hose would certainly be more convenient then the bucket method and that way it's just two steps, add the appropriate amount of water conditioner and the slowly add the water from the hose and it removes the step of aerating the water before it goes in. I've got an external tap not too far away from the room where my tank is so I might give that a go as well.

 

[itiwhetu]

Fish love live plants

 

[TheGunzel]

Yes you can use a spare airline from the tank or air pump to aerate tap water and dechlorinator.

-------------------
Filters should be cleaned at least once a month. Every week or every couple of weeks is fine if the filter is established and more than 2 months old. To clean the filter just squeeze the filter materials/ media out in a bucket of aquarium and re-se the media. Tip the bucklet of dirty water on the lawn.

If you have filter pads, they eventually start to break down and fall apart. You can replace them with sponges for other brands of filters. Just find a filter sponge that is slightly bigger than the filter pad and use a pair of scissors to cut it to size. Sponges get cleaned in a bucket of tank water just like other types of filter media. If you have space in the filter, you can add sponge now so it will have some bacteria when the filter pad/s need to be replaced. Just replace one pad at a time and wait at least a month before replacing any other filter pads.

-------------------
You can bleach plastic or glass ornaments with household bleach. Just leave the ornament in a small container of bleach and water, then rinse the item off really well under tap water and let it dry in the sun for a day. When it no longer smells of bleach, give it another rinse under tap water and put it in the tank.

Some ceramic ornaments have pores in the base and bleach can enter these pores and leach out slowly so try to avoid bleaching ceramics.

The colour on some ornaments is not fixed and bleach can cause it to fade. So if you have a nicely coloured ornament, maybe avoid bleaching it.

*NB* If you use bleach, try to use it outside or where there is very good airflow. Do not use bleach in a closed room with no airflow.

*NB* Wear safety glasses and rubber gloves, and if possible a plastic apron when using/ handling bleach.

-------------------
Regarding the fish, it could be alkalosis, acidosis or gas bubble disease. I've seen it before but can't remember what it is and I no longer have access to my books or notes on my computer because it died a few months ago with all the data on it.

The white slimy stuff on the fish is excess mucous.

The eyes on the bronze Corydoras are sticking out a bit, which suggests some pressure build up in the skull.

I think the bubbles on the skin are from alkalosis or gas bubble disease (a bit like nitrogen bubbles in divers causing the bends).

----------
What sort of filter is on the tank?
Does it have hoses and connectors?
If yes, are these well connected or do they leak a little bit and let air get drawn in?

Do you add anything to change the pH of the tank water?

Do you check the pH of the tap water and aquarium water?
You should check the pH before water changes to make sure the water company hasn't done something weird to the water. If there is a big change in pH between the aquarium water and the tap water, it can cause acidosis (where the pH drops suddenly) or alkalosis (where the pH goes up suddenly). The same thing can happen if you add pH buffering solutions to an aquarium. If you change the pH too much too quickly, you can cause acidosis or alkalosis.

Do you have any wooden airstones or airstones of any type in the tank?

Do you have a power head in the tank that sucks air into the water?

I'll go back to giving my filter pads a clean every few weeks as per your advice. As to replacing them with a sponge, the pads I'm using have carbon pellets in them. My understanding is that the carbon absorbs impurities from the water so how would I still get that benefit if I replace the pads with just sponges?

I've been told a cartridge filter external to the tank is a much better set up, in your opinion is that true? I'm fine with spending a few dollars if the benefit is there.

The filter in the tank is an Aqua One power head filter that hangs in the corner of the aquarium. The inlet side of the pump is just a straight pipe from the bottom of the head that runs vertically down into the tank. All of the inlet side of the pump is immersed in water so it shouldn't be able to draw any air in.

I also have an air stone in the center of the sponge filter that sits on the bottom of the tank. I'm not sure of what materials it's made from, it's bright blue in colour so I'm guessing something synthetic?

I haven't tested what the PH of my tap water is and I will certainly do that. I had a period of about 2 months when I was testing the water about twice a week (this was while the tank was cycling so I was trying to get my head around the chemistry changes in the water) and there weren't any noticeable changes in the PH during that time as I was changing the water. That's not to say my tap water PH isn't markedly different from the tank water PH value and that by adding the tap water the two PH values average out. I'll test the tap water ASAP and at least I'll know.

I did try and lower the tank PH slightly at one point using some Seachem Neutral Regulator but I did it a couple of times using the recommended dose and it didn't seem to make any difference so I stopped as the PH wasn't overly high anyway.

 

[kiko]

get rid of the fake plants and use real ones...and get rid of that filter
and replace it with a dual sponge filter --->

as most people will literally kill all the beneficial bacteria while cleaning a single sponge
this way you can pull out one...clean it...the other week you do the other one...
but as these things barely filter anything...as it pushes very small amounts of water up through the tube using an air pump
you can literally go weeks without even cleaning them....
as for chasing perfect water with water changes every 4 days on a 1 year old tank....
last time I changed my water was 3 weeks ago if I'm not mistaken...
my water is added straight from tap through a shower head filter...
I don't add any type of chemicals....and my water is crystal clear
as for 30% water changes and then adding chemicals to fix it....just stop doing it...
10% water changes weekly should be more than enough...
need better water? get better filtration...filter floss does wonders for it...
hob filter or canister..or better...build a sump in your tank xD
people need to understand...the very water you drink...is the same water your neighbor used to pee in 10 days ago
comes from the lake/river filtered through a million filters and back to your tap it goes....
filtration is key for good water keeping....lots of filtration can never be a bad thing xD

 

[Essjay]

My understanding is that the carbon absorbs impurities from the water so how would I still get that benefit if I replace the pads with just sponges?

The main things removed by carbon are fish medication and the brown colour that leaches out of wood. Most people do not use carbon at all, and if they do it's to remove medication after treatment has finished. It's a money spinner for the equipment manufacturers.

 

[TheGunzel]

OK, thanks everyone for their input so far.

Oblio asked a question about my tank water hardness earlier in this thread so I went a purchased an API hardness test kit.

I've tested both my tank water and my tap water and the results are -

Tank water

• KH 89.5ppm
• GH 161.1ppm

Tap water

• KH 53.7ppm
• GH 89.5ppm

My tap water PH measured at 7.0.

From reading the test kit instructions it seems that my general water hardness is a bit high for both my neons and also for the plants in the tank.

It was suggested in a reply above to put more plants in my tank and I'd like to but I haven't had much luck getting them to grow, I'm hoping if I can get the water hardness down that will change.

I've turned the tank heater down and the water is now at 22 degrees Celsius.

Is my PH value of 6.4 a bit low for Corydoras and Neons? I want reduce the water hardness before getting some more Corys but I'm wondering whether I should also adjust the PH up a little before then as well.

 

[Oblio]

Your params are fine for Corys and Neons

Corydoras aeneus – Bronze Cory (Corydoras schultzei, Corydoras venezuelanus) — Seriously Fish

www.seriouslyfish.com

Paracheirodon innesi – Neon Tetra (Hyphessobrycon innesi, Cheirodon innesi) — Seriously Fish

www.seriouslyfish.com

 

[DoubleDutch]

What are they fed ?

 

[TheGunzel]

What are they fed ?

Hello DoubleDutch, I'm feeding them Sera Tropical Flakes.