Increase in Nitrite

[paulc]

I've got a 92 litre tank, cycled 4 months ago, stocked with -
2 clown loaches
3 black widows
3 platies
3 mollies
2 algae eaters

I do fortnightly water changes but on testing the water before yesterdays change the nitrite level was very high, almost in the toxic scale. I did a quarter water change, cleaned the filter but the nitrite level is still very high today.

I'm just going to do another water change
I've read that salt can help reduce nitrite?
How often do I need to change the foam thingy in the filter?
Do I need to add charcoal to the filter?

Any other advice is much appreciated
Thanks
Paul

 

[Blazeherd2306]

Do you overfeed your fish? How often do you do water changes? Also clown loaches produce a lot of waste and what type of filter do you have?

 

[Fishyfanatic]

What are you exact levels for Ammonia, Nitrite, and Nitrate?

 

[paulc]

Do you overfeed your fish? How often do you do water changes? Also clown loaches produce a lot of waste and what type of filter do you have?

Normally I feed once a day sometimes twice
I do fortnightly quarter tank water changes
The filter is a Rena Internal 70 Gph / 300 l/h

Do I need to add new charcoal to the filter?

 

[paulc]

What are you exact levels for Ammonia, Nitrite, and Nitrate?

Ammonia - the fish shop said I didn't really need to test this as Nitrite is more important - bad advice?

Nitrite - the test kit is in bands so I haven't got an exact reading but it is between 0.5 - 1.5 mg/l

Nitrate - as above between 0 - 10 mg/l

 

[Fishyfanatic]

I take it you are using the test strips. What you need to do is purchase a Master Test Kit. The results are VERY accurate and it is alot cheaper than the test strips. I'm not sure of what is available in your area, but an Aquarium Pharmacuticals Master Test Kit is top notch. Make sure it tests for Ammonia, Nitrite, Nitrate, and pH.

From your readings, your tank is not cycled. To have a cycled tank, the ammonia and nitrites should be 0 and Nitrates should be between 15 and 30. Ammonia should be tested because it is toxic to fish at high doses. AND, having ammonia too high can cause the tank cycle to stall. Nitrites are very toxic to fish and should be tested for, but so should Ammonia. Nitrates are not as big as a concern as long as you don't have an over stocked tank and keep up with weekly 20% water changes. They should still be tested, but during the cycling stage it's not needed until after you should 0 Ammonia, and your Nitrites start to decline.

During the cycling process, you should not be doing gravel vacs or cleaning the filter. If you are, stop. The foam doesn't need to be replaced unless it starts fall apart. You can rinse it in use tank water, but not tap water. The chlorine in tap water will kill the good bacteria.

AC is not needed in filters unless you are removing meds. IMO, I'd use Ceramic rings instead of AC.

 

[malkore]

Let me clear up a couple things:

Carbon/Charcoal does NOT do anything for ammonia, nitrites or nitrates. It absorbs odors and some chemical compounds (like medications). It cannot absorb ammonia, nitrites or nitrates. If carbon gets really old it could become inhabited by the bacteria that converts ammonia to nitrite/nitrate, but that's long after the carbon has lost its effectiveness (5-7 days).

Salt and nitrite: salt does NOT affect nitrite in the water. salt does help fish cope with the effects/stress of nitrite poisoning.

Ammonia: Ammonia is the MOST toxic compound created in the aquarium. ammonia toxicity will burn the fish's gills permanently, and they can never repair the damage. thus they lead shorter lives. Your LFS doesn't seem to know much about fish keeping.

You either have an uncycled tank, damaged your bio filter, or something is dead and rotting inside the tank and your bio-filter isn't large enough to cope with it all at once.

 

[SteveM]

300 l/h filtration on a 92l tank might be a little on the low side also. Most people here shoot for filter flow 5-10x tank volume. This might be why your biofilter can't keep up with waste production.

I think the toxicity of ammonia really depends on your water. Most test kits measure total ammonia/ammonium, and while ammonia is quite toxic ammonium is not. The ratio of the two present in the water is mostly determined by the temperature and pH. So if you have pH of 7 or lower I think I would be more worried about nitrite than ammonia. If you have a high pH then ammonia is quite deadly and I'd worry about it more.

Here is a link that explains ammonia toxicity:
http://www.desertaquaria.com/content/reference/ammonia.htm

 

[paulc]

I'm really puzzled now as the tank was fully cycled 4 months ago according to the nitrate/nitrite readings. There is nothing rotting so how can I tell if the bio filter is damaged and what do I need to do?

I'm still confused with filters, do they last forever? what bit needs to be replaced?

I'll continue with water changes and will add some salt.

Sorry for all the dumb questions

 

[SteveM]

Well, its a somewhat circular argument, but you can tell that the biofilter is damaged by the presence of ammonia or nitrite.

As far as filter replacement, if you choose to use carbon it needs to be replaced regularly - probably every couple weeks. Many people don't use it at all and some people can't imagine not using it, so it's really your call. Any sponges in your filter should be routinely cleaned in tank water that you have removed during a partial water change - they only need to be replaced when they are torn or just plain worn out. Floss usually needs to be replaced pretty often as you can't really clean out the fine particles effectively. Whenever you change or clean any part of your filter you are disturbing the biofilter, since it is growing on everything that gets oxygenated water flow. Best thing is to never change it all at once.

(edit) And the only dumb question is the one you don't ask

 

[Fishyfanatic]

No question is a dumb question. You're trying to help your fish survive in the best possible environment, nothing dumb about that. Every one of us have been in the same boat as you are right now. They either asked the same questions, or read about it. Don't feel dumb. After all, that's what we are here for.

I'm still confused with filters, do they last forever?

They do not last forever, but you can keep using them until they fall apart.

what bit needs to be replaced?

The sponge can be kept until it falls apart, but the AC cartridge doesn't even need to be used. You can replace the AC by cutting open the top of the cartridge, dumping out the AC, and pouring in Ceramic rings. This way it doesn't need to be replaced until it falls apart.

how can I tell if the bio filter is damaged and what do I need to do?

Have you recently added chemicals or meds to the tank? Did you clean out the gravel really well and change the cartridges at the same time? When you say your tank was cycled 4 months ago, were your reading Ammonia 0, Nitrites 0, Nitrates 10-30? Some peopel confuse the cycling of the tank with "cycling" of water. "Cycling" of water is pouring water into the tank, letting it sit for a week or so after adding dechlorinator, then adding fish.

 

[StyleUK]

They're not dumb at all, I started with a tank likes yours also, just smaller.

If your tank is produced or redistributed from Rena, then I know for a fact that all of their tanks come with not nearly enough filteration to handle any of their tanks. Mine came with a filter that was pretty much useless with the tank size I had.

I'd recomend buying a Hagen Fluval Plus 4 if you like internal filters, if not buy a Hagen Fluval 204 or 304 canister filter, a lot more powerful and would help you with your filteration problem. Do not remove your other filter though if you do buy a new one, because you would loose all of your good bacteria.

Filters do not last forever, nothing does, you do not need to replace anything on a filter unless it's broken, or just stops working altogeather, if this happens check the flow and look for any obvious problems, failing that you need a new filter. The foam pads inside your filter are the only thing that needs to be replaced, I change mine every 4 months, but only if I really need to.

Sometimes if you clean your substrate or filter heavily this can start a mini-cycle, I would carry on doing a PWC of 10% every 2 days until the cycle has finished.

Are you adding de-chlorinator? If your not i'd advise getting some, as fish do not like chlorine at all and will kill good bacteria, if you don't want to buy any, just leave enough water for your PWC in a bucket for 48hours it will get rid of the chlorine and be safe to put into your tank.

Hope this helps, sorry if i've overposted some of the other members, I was quick reading because i'm late for my job interview.

 

[paulc]

I'm still confused with filters, do they last forever?

They do not last forever, but you can keep using them until they fall apart.

what bit needs to be replaced?

The sponge can be kept until it falls apart, but the cartridge doesn't even need to be used. You can replace the AC by cutting open the top of the cartridge, dumping out the AC, and pouring in Ceramic rings. This way it doesn't need to be replaced until it falls apart.

Can I leave the AC in the filter or does it cause damage if it is not replaced?

how can I tell if the bio filter is damaged and what do I need to do?

Have you recently added chemicals or meds to the tank? Did you clean out the gravel really well and change the cartridges at the same time? When you say your tank was cycled 4 months ago, were your reading Ammonia 0, Nitrites 0, Nitrates 10-30? Some peopel confuse the cycling of the tank with "cycling" of water. "Cycling" of water is pouring water into the tank, letting it sit for a week or so after adding dechlorinator, then adding fish.

I did a fishless cycle which lasted 6 weeks (as I didn't know what I was doing ). The readings were Ammonia 0, Nitrites 0, Nitrates 10-30 then I introduced fish.

I did add meds for white spot and gave the filter a really good clean about a fortnight ago. New fish were introduced only 3 weeks ago so perhaps this combination has led to the problem.

 

[paulc]

If your tank is produced or redistributed from Rena, then I know for a fact that all of their tanks come with not nearly enough filteration to handle any of their tanks.

It was a Rena package tank, filter, heater etc. Thanks for the advice I'll look at your suggestions

Sometimes if you clean your substrate or filter heavily this can start a mini-cycle

I think this is probably the answer

Are you adding de-chlorinator?

Yes I am

Hope this helps, sorry if i've overposted some of the other members, I was quick reading because i'm late for my job interview.

Yes it really helps, I appreciate your advice. Good luck with the job!!

 

[Fishyfanatic]

Some meds can completly kill your bacterial colonies. Maybe that's what contributed to it also.

You can use the AC if you want, but ceramic rings are a much better option, unless you are removing meds.

Also, you need to get a Freshwater master Test Kit. They are relatively cheap (about $20) online, but can range upwards of $40 at the lfs. Again, not sure how much they run around your area though.

BTW- This may sound like a dumb question, but what is a fortnight?

 

[patagonia]

i believe fortnight means 2 weeks.... no....?

 

[paulc]

i believe fortnight means 2 weeks.... no....?

yes fortnight = 2 weeks

 

[Fishyfanatic]

Thanks for clarifying. I always wondered what it meant.

 

[paulc]

ok hopefully final question

I went to the fish shop and the guy there told me that the carbon needs to be replaced in the filter every few months as it stops absorbing, becomes saturated and then becomes toxic.

Is this correct as comments above seem to contradict this advice and I've lost a bit of faith in the fish shop?

Thanks
Paul

 

[mattrox]

You can just take the carbon out and leave it out. You only really need it when removing medication from the water. The lfs wants to sell you product, and it is true, to benfit from AC, then you need to keep replacing it. But you can have a healthy aquarium without it.