Sudden Cloudy Water, Nitrite And Nitrate Spike, Cloudy Again After 2 Water Ch

You have to get the ammonia and nitrite levels down to acceptable levels. 0.50 nitrite is too high. Keep doing water changes whenever the levels of either of these substances is above 0.25.

Check your filter. You need to check that the output is functioning correctly. This will confirm you have a sensible flow through your filter.

Cloudiness in a tank is usually a sudden bloom of bacteria. This would seem to imply that there is some organic compound on your fern that has provided food for these types of bacteria to thrive. This spurt in bacterial growth may affect the oxygenation levels in your water, this in turn will affect your filter bacteria. Add an air-pump if you have one.

I would also recommend that you remove the fern, at least for now.

Bit confused by your comment 'you have to get ammonia and nitrite levels down', as mentioned -  currently (ammonia 0 -which it's been at every test today (is that odd for it to be 0 if the nitrite is up?), nitrite at last test 0.25) so assume I don't need to do any more water changes at the mo?

Nitrite at 0.25 is still too high.  If you think about it, there is nowhere for it go but up, so as soon as you have done the test at 0.25, the actual value is higher.  It's a bit Quantum Physics but...  I threw in the ammonia bit because it's part of the golden rules for fish-in cycling and it sort of slipped in. As to whether it's odd for ammonia to be zero; I don't think so, you have enough bacteria to handle the ammonia, but not enough of the other bacteria to handle the nitrites. It's a typical response when you have an increase in ammonia load because the ammonia eating bacteria grow so much more quickly than the nitrite eating ones.

I Read somewhere on the net that you can make the nitrite keep spiking if you continously keep changing the water?  Is that true?

It's not something I have heard about, and I can't see any logical reason for it to do so. Perhaps someone else has some ideas but weekends are generally a bit slow.

Hi Sue and Steve

Thanks for all your help. Been out all day today and water was miraculously back to normal clear state this morning.  All fish looked happy so we left it and have just seen your messages.  Just about to test the water now, will report back when it's done.  We haven't done anything to the filter or the gravel (should you 'deep clean/hoover' the gravel ever?  I've also read about sand substrate needing to be completely removed as it can get 'nasty'.   Is that another myth?

As for where I read the other thing about too many water changes causing nitrite spikes, I was googling fast in panic when the fish were dying and my husband was changing the water, can't remember where I saw that but did think it was odd!

No more dead fish when we got home this evening so I'll go test now and be back in a mo with results . . .we can still only think it's the new 'supa fern' that caused the problems as it hadn't been rinsed.  Says in big letters on the back of packet 'harmless to fish'  yeah right! 

Gald to hear your water is looking good. keep an eye on it for a few days to be sure. It could have been the dead fish. As Steve said, the bacteria that cause the bloom live on organic matter. A dead fish is organic matter and if your tank is like mine - warmer than usual during the heatwave - the fish could have decomposed faster creating more organic matter in the water column. The plant would also have contained organic matter (plasticisers) which could have caused it. Perhaps the hot weather/tank water allowed to the bacteria to multiply faster than they would normally have done.

Try soaking the new plants in a bucket of water and check the ammonia and nitrite levels in the bucket. A bit of tank water would be better than tapwater for this test because any bugs in the tank water would react the same way in the bucket as in the tank. That would show whether it was the plant or not.


Since you have no live plants, you should be cleaning the gravel at every water change. With only synthetic plants, the gravel does not need to be deep and shallow gravel is easier to clean. You'd be amazed at the amount of muck that collects in there over a week - fish poo, uneaten food etc. If you haven't been cleaning it, start carefully and slowly. Do a bit every time you do a water change, but be careful not to churn the gravel up and throw this muck up into the water. Once you have got round all the gravel, start at the first patch again and do more each time as there won't be as much muck as the first time. Within a few weeks, you'll be able to do the whole lot in one water change. If you had live plants it would be different as you'd need deeper gravel for the roots, you couldn't hoover too near the roots, and the plants would use a lot of the muck as plant food.

If you wanted sand, again you wouldn't need it deep with no live plants. I changed to sand a couple of years ago and mine is shallow as all my plants are the kind you have to attach to decor not plant in the sand/gravel. I have not had a problem with things building up in the sand. You clean sand by hovering the tube about half an inch above the gravel and swirling it in little circles which lift the muck off the sand where it can be sucked up. The downside to sand is all the muck you don't see between the bits if gravel lies on the surface in full view. In my case it's worth it as my loaches, apistogrammas and corydoras prefer sand.
If you do ever change to sand and the gravel still has a lot of muck in it, ask about the best way to go about the change 



Edit:
Can I ask (sheer nosiness  ) what are pink neon tetras? I can't find anyhting on google but ordinary neon tetras.

You are quite right Steve. I wasn't aware that you could get plants like that. I usually buy synthetic plants in real shops so I can feel them first, and I've not come across this type. I've just googled them and see what you mean. The problem could be either the fern itself or the dye used.

Now I know, I would definitely suspect the plant.

Clean the gravel every time you do a water change.  You push the wide end of the siphon tube into the gravel and watch until the muck stops coming, then move the tube along a bit and clean the next bit. If there's a lot of muck to clear, you won't be able to do much before you've emptied the water you want to take out, so next time, do a thorough deep clean on the next patch. Keep doing this till you've been round the whole tank. Once you done that, start at the first place again with the following water change. You should be able to do a bigger area each time on the second circuit of the tank as there won't be as much muck to remove. After several, perhaps tens of water changes, you'll find you'll be able to get round the whole tank in one water change. The important thing when you first start is to move the siphon tube slowly and carefully. You don't want to kick the muck up into the water or you could cause another ammonia and/or nitrite spike.

You can have your gravel as deep as you like, but if you've no live plants having it shallower means less gravel to clean, and you take up less water volume.


Aha, the tetras are albino neons, though shops will give them fancy names 

Can I just warn you before you get a betta that your current fish are almost all shoaling fish and should be in groups of at least 6. The only one that isn't is the platy. It may be that you started out with shoals and have lost some since you got the tank but you would be better off choosing one of the harlequins neons cardinals or barbs, rehome the others and get more of the one you want to keep. A shop might give you part-ex, as it were. If you were to increase all your sholaing fish to 6 each, that would put you at 138% stocked, using oversized internal filter in the community creator.

And be careful about keeping a betta in with other fish. Some people find neons and cardinals nip betta's fins, and possibly the barbs too, even though that species is not a very nippy one.

Push the end of the tube into the gravel, wiggle it a little bit to loosen the gravel and just watch as the muck goes up the tube. The reason I'm cautioning you to be careful is that I have read tales of people who have gone mad during a gravel clean and kicked up a huge amount of mess into the water. This fish poo and uneaten food is then exposed to the bacteria that eat organic matter and turn it into ammonia, then next thing they know they have an ammonia spike, followed by a nitrite spike. If you take care to keep the mess in the gravel then in the tube, you shouldn't have a problem.

It is a problem when most of a shoal dies and leaves just the odd couple of fish. If you are happy to keep them, wait until they all die of old age, then get another shoal. I just wanted to check that you hadn't been led astray by a shop telling you that you could have one of those, two of those etc.



Bettas are iffy fish in community tanks. They have very variable personalities. Some are so laid back they get badly bullied, others are so aggressive they kill anything that moves, and of course everything in between. I would be inclined to try a betta with one proviso - have a back-up plan just in case. Something as simple as a fry trap (with a cover, home made will do, as bettas can jump) so that if the betta attacks the other fish or vice versa you have somewhere to separate him till you decide what to do (return him to the shop or get a 20+ litre tank just for the betta)


A thought about plants - if you want to try real ones, you don't have to plant them. I have java fern and anubias, both of which have to be grown tied to something as the roots rot if you plant them. Mine are fastened to wood and plastic ornaments. If I can grow them, anyone can