Ammonia issue for weeks - plant substrate?

[Airecl]

Hi all

I have had a tropical tank 230L running cycled for a few months and one of my Cory cats died whilst I was out. Found it half eaten so scooped it out and as much stuff as I could.

Over the next few weeks my shrimp died and some of my fish. Measured the ammonia and it was 3-4ppm (acidic water so hopefully ammonium)

Been doing large water changes, most of my fish have been moved into a happy cycled hospital tank and they’re ok.

Tried checking ornaments, under everything - haven’t been able to find why the ammonia keeps rising - dosing with bacteria and prime to try and keep it under control between water changes.

Now I’m thinking it could be down to the substrate - I have white (fish tank) sand, underneath I have Tropica plant growth substrate - some of it has leaked up above the sand.

I’ve also got quite a few bits of driftwood in there too.

Getting desperate tbh! Really want to try and sort it out.

Any ideas why the ammonia is going from 0.5ppm to 2-3 over 48 hours?

 

[Colin_T]

Hi and welcome to the forum

Is there any nitrite and nitrate?
Is the filter working properly?\
Is there lots of aeration/ surface turbulence?

You can test the substrate by putting some in a bucket of tap water that has no ammonia and see if there is an ammonia reading after 24-48 hours. You can do the same with driftwood, which can sometimes rot and release ammonia.

If the pH is too low it can inhibit the beneficial filter bacteria. If there are no fish in the tank increase the pH to 7.0 and see if the ammonia continues to go up.

 

[Airecl]

Hi Colin

Thanks for the welcome

Nitrite is 0, nitrate seems to be between 10-25 usually. Sometimes a bit more.

Unfortunately there are still a few fish in there so I don’t want to upset them.

I’ll try testing the substrate - thank you!

 

[The Lumpfish Guy]

Unfortunately there are still a few fish in there so I don’t want to upset them.

What is the stocking of the tank? numbers and fish wise?

 

[Airecl]

What is the stocking of the tank? numbers and fish wise?

At the moment the tank contains 11 neon tetras and 6 glass catfish. Total volume 230 litres.

 

[The Lumpfish Guy]

At the moment the tank contains 11 neon tetras and 6 glass catfish. Total volume 230 litres.

Ok, just checking as you said there were still a few fish in after a few had died

 

[Colin_T]

11 neons and 6 glass catfish isn't going to be an issue or cause ammonia issues in a 200litre tank.

 

[Byron]

The substrate may be the cause. Another is the bacterial supplement. Knowing the pH is also important.

Substrate. While Tropica is a reputable brand, I cannot find what exactly is in this substrate. If there are organics, such as would be in soil substrates, these will increase ammonia considerably and fish will die as a result until the organics are depleted and ammonia no longer occurring.

Bacteria. Depending what and how much, this too can cause increases in ammonia.

The pH is important because it can affect the nitrifying bacteria, as well as the toxicity of "ammonia" or "ammonium" present. Most test kits measure both as "ammonia," though ammonium is basically harmless.

Prime is not a medication, and it will harm fish in excess. Only use it at a water change, and for the volume of water changed. On the ammonia, Prime converts it to the harmless ammonium, but this is temporary, 24-36 hours according to Seachem, after which if still present it can revert back into ammonia. An acidic pH will maintain ammonium.

The more substances we add to the enclosed system of an aquarium, the greater the chances of interactions that can be detrimental. One reason I never recommend so-called plant substrates. And keeping any additives minimal is also wise.

Colin's suggestion to test the substrate may show something, but outside the biological system of an aquarium with all the other factors this may or may not tell you anything.

Nitrates around 20 ppm are on the high side, and over this will be problematic for many fish. Unless these are present in your source water, you want to keep them as low as possible and certainly never higher than 20 ppm.

 

[The Lumpfish Guy]

11 neons and 6 glass catfish isn't going to be an issue or cause ammonia issues in a 200litre tank.

Yeah, thought I would ask

 

[Airecl]

Thanks all

Unfortunately found it hard to get any substrate out from under the sand cap so left it be, have planted several more live plants and lowered the amount of 'treatments' e.g. bacteria/prime and just using water conditioner when changing and the ammonia reading seems to be coming down gradually (~1ppm)

Hoping the plants are helping this.
Keeping on top of my nitrate also

 

[NickAu]

If there are no fish in the tank increase the pH to 7.0 and see if the ammonia continues to go up.

How exactly is the OP meant to do that? What magic product would you suggest the OP uses?