Disaster! Serious Substrate Situation!

[mrsblack10272]

Hey long time Forum!
I have an almost 15 gallon - 65 litre freshwater tank - 60x30x30cm.
On 18th September this year I went on a long break with family after being very ill. I planned to stay with my brother for 1 week and so before I left I did a 20% water change (as I do usually) and cleaned the heater, and any plants and decor that needed cleaning. I didn't however clean the gravel. (I have pretty fine gravel) because I had done a full siphon 6 days earlier. I set up an automatic feeder with a weeks worth of flake and tablet food and fed them live food the day before. All my fish looked great (trio of honey gourami and a shoal of 10 pygmy cory) infact my pygmy corys had just bred a week earlier and the majority of their eggs got eaten by my gouramis who were also showing spawning behaviour.
I set off for my holiday break, feeling reasonably confident that fish would be ok.

After a week, I decided to stay away for another three weeks, the break was doingme the world of good!

So I emailed my trusty neighbour, who had looked after my fish before having had some of her own.
She said she would gladly help me out, feeding my fish every day, water changes once/twice a week, gravel cleaning once a fortnight and other cleaning etc. So again I felt confident.

I just got home yesterday to a shock. My fish tank is filthy with algae, the gravel is also a complete mess with debris everywhere, I have 5 pygmy cory missing and the remaining fish look awful - they are very thin and inactive.

I felt awful so went next door to find out what happened. Her sister answered the door. Apparently the day after I talked to her my neighbour came down with flu and was rushed to hospital with suspected swine flu. Obviously I feel awful for her but I am alittle frustrated that her sister or anyone else let me know!

Anyway yesterday I set about cleaning and feeding. I tested the water first and it was horrendous. The ammonia was so dark in the test tube it was off the scale and the nitrates/nitrites were bad too, both reading about 50.

After feeding my starving fish I called it a night. I got up today ready to give the gravel a good siphoning when I noticed something. Several cm below the dirty top layer there are numerous filthy black patches that almost look like packets of mould but black. Out of the ones I can see there are about 10.

Help!? What should I do? I don't want to disrupt the gravel in case it releases any nasties and kills my fish. If it helps I have an empty 5 gallon quarantine tank? Please help asap! X x

 

[CezzaXV]

If I were you, I'd take the fish out and put them in your quarantine tank for the moment, and give the tank a complete clean, since you're going to have to get all that water out anyway.

 

[pablothebetta]

+ 1 on that.

 

[mrsblack10272]

Thankyou for very quick replies!

I thought about that but are you sure it would be ok?
Surely getting rid of ALL the water would mean basically setting up a new tank. What happens to all the developedgood bacteria?
Xx

 

[lucasluke]

I dont see how your ammonia and nitrites shot up if your tank was cycled. Did you cycle it?

 

[fluttermoth]

The good bacteria live in your filter (that's why you only ever clean it out in old tank water), so as long as you don't let the filter media (sponges or ceramic noodles or whatever) dry out, the bacteria will be fine

I dont see how your ammonia and nitrites shot up if your tank was cycled. Did you cycle it?

Obvoulsy the overfeeding and muck was more than the filter bacteria could cope with. Hopefully they (the bacteria) won't have died

 

[HayzH]

I dont see how your ammonia and nitrites shot up if your tank was cycled. Did you cycle it?

+1

 

[mrsblack10272]

Yepp definatly I have had this tank for about 2 maybe 3 years now. When I set it up, I put some recommended 'filter startup' on my filter sponge on day 1,4 and 8. I left the tank running for two weeks and did a 5% water change after the first week.
I then bought a trio of cherry barbs and kept them in the tank for about 6 months. I then bought my trio of gourami and then 2 months later bought my shoal of pygmy corys. 5 at one time with a fortnight gap. The day before I bought the first batch of pygmys I put the trio of cherrys to a friend of mine who has a 20 gallon dedicated to breeding a shoal of them.

I have never had any problems with my tank before now and still have the original fish still with no deaths since recently and not a single disease has entered my tank or caused problems. Infact both my pygmy corys and honeys have bred a number of times, and I have also successfully reered a good 2 batches of fry to adulthood with few deaths. And made profit from selling them too!

Really sad today. But also amazed at how any fish have survived.

 

[mrsblack10272]

So at the moment I am thinking ......
Catch my fish and put them in the quarantine tank. Take out around 50% of the water and keep it in a large tub that I have, along with the filter heater airstone tubing and decor. I will then fully vacuum the gravel with the remaining water. then tip it away. Put everything back in the tank including the saved water and top up with new water.
Then out fish back in tank.
How does this sound?

Ty x x x

 

[fluttermoth]

Sounds perfect; good luck!

 

[TheRedDarren]

The good bacteria live in your filter (that's why you only ever clean it out in old tank water), so as long as you don't let the filter media (sponges or ceramic noodles or whatever) dry out, the bacteria will be fine

I dont see how your ammonia and nitrites shot up if your tank was cycled. Did you cycle it?

Obvoulsy the overfeeding and muck was more than the filter bacteria could cope with. Hopefully they (the bacteria) won't have died

+1

 

[coldcazzie]

So at the moment I am thinking ......
Catch my fish and put them in the quarantine tank. Take out around 50% of the water and keep it in a large tub that I have, along with the filter heater airstone tubing and decor. I will then fully vacuum the gravel with the remaining water. then tip it away. Put everything back in the tank including the saved water and top up with new water.
Then out fish back in tank.
How does this sound?

Ty x x x

if you have ammonia "so dark it was nearly off the scale" then you need to be doing more than a 50% water change (which is what you'll be doing by saving half the water and putting it back) - you need to be doing more like 2 x 95% water changes back to back.

As fluttermoth said, it is the filter that is cycled, not the tank or the water. You can replace the water and clean the tank with no effect on the cycled filter, as long as you clean and replace water with dechlorinated, temperature matched water.

I agree that in this case, keeping the fish in a spare tank would be prudent, with a small amount of their original water and topped up with new. Then siphon out all the rotting gunk, food, dead fish etc. Refill the tank, and then siphon and gravel vac again. You can't do it too many times in this kind of situation. Make sure to put your filter in the smaller tank with your fish while you do it.

The stress that may be caused by being moved to another tank is far outweighed by the damage that will be caused by leaving them in polluted water and not changing enough of it.

Good luck

 

[CezzaXV]

I agree with Cazzie. Normally we'd advise against doing a complete water change as you risk exposing the fish to things like pH shock, but with those levels of ammonia and nitrite in the tank, the water simply can't stay because it's poisoning your fish.

The bacteria are in your filter, if there are any left. It's impossible for us to say whether the bacteria will have died during this period or just overloaded and there was more in the tank than they could deal with. If I were you I'd test the water at least once a day for a little while after changing it, as if your ammonia and nitrite levels keep creeping up that means the bacteria have died and you'll need to do a fish-in cycle.

 

[mrsblack10272]

Thanks I suspected as much but as you said, I was worried about the water quality change affecting the fish. To begin with I was planning on doing a 50% today and a.
further 50% every day till maybe Monday?

Having read this I think I might do a bigger change today.

Part of me is thinking to hell with gravel! And swap to sand. If I were to 'kill two birds with one stone' today, do I need to do anything differently? Do I still need to vacuum the gravel before taking it out? X x

 

[the_lock_man]

Thanks I suspected as much but as you said, I was worried about the water quality change affecting the fish. To begin with I was planning on doing a 50% today and a.
further 50% every day till maybe Monday?

Having read this I think I might do a bigger change today.

Part of me is thinking to hell with gravel! And swap to sand. If I were to 'kill two birds with one stone' today, do I need to do anything differently? Do I still need to vacuum the gravel before taking it out? X x

As stated, if your ammonia is off the scale, changing 50% is not going to make an appreciable difference - 5ppm ammonia is very little different than 10ppm, in terms of it's bloomin' horrendous for the fish.

I would agree wholeheartedly with Cazzie - your remaining fish in the small tank, with the filter, and as much fresh, dechlorinated water as will fit in. If you're going to change to sand, then yeah, why not? Strip the gravel out, wash the floor of the tank thoroughly, pop in the sand, and refill. Pop the fish back in.

And then test again, to be on the safe side.

Edit: Thinking further, stripping out the gravel will naturally be a better clean-out than leaving the gravel in, so I say go for it.