Bizzare Ammonia spike?

[lukeMH]

Hi,

The tank I am refering to is a well established tank with a mature filter (2-3 year old media)

There are no problems I can see with the fish, they look happy and healthy, but as I was testing my other tanks (as one does have a nitrite spike due to a filter clog) I thought I would test my main tank at the same time.

The water stats read Ammonia 5+ Nitrite 0.25 Nitrate 5

It is 8 days since the last water change (30-40%)

The filter was last cleaned 8-12 weeks ago and I only clean the foam/floss not the bio-media. The flow rate is currently very good so the filter is not in need of another clean.

I don't see how this has happened, I always dechlorinate the water, though I have changed brand a few times recently (aquaplus to aqasafe) could that cause any problems?

There are no meds in the tank apart from abit of melafix as the giraffe cat cut itself on a rock.

I need to find out what on earth could have caused this and fix it quickly as I have some real valuable fish + fish I have had for a long time so do not want any of them to suffer )

Kind Regards

Luke

[corinneangela]

Hmmm.. could it be because you don't clean the bio media? It does need cleaning from time to time.. not a thorough scrub, but a rinse in dirty tank water... when you say bio media.. what bio media do you use?

You're clearly going through a mini cycle which means either your filter can't cope with the bio load (have you tested this tank recently before this? Or have you added any new fish?) Or, for some reason, some of the bacteria have died off.. I've never used Melafix.. it isn't an anti-bacteria med is it?

The change in dechlorinator wouldn;t have caused it.

For now, do more water changes to dilute the ammonia and nitrite... maybe a couple or more a week.. and keep an eye on the ammonia and nitrite..

[Scarlet]

Could you have had a powercut?

[SBA]

check the pH and KH, could be a pH crash has affected the filter bacteria. if so the pH will be low so the ammonia won't be that harmful to your fish, but you will need to buffer the KH up to around 4dKH.

HTH
Ade

[dumber]

Ammonia at 5+ is sky high and would almost certainly have shown noticeably on at least some of your fish surely? My first thought would be your test kit. Have you had it a while? Try a different test.

[lukeMH]

I have done a 50% water change yesterday and a 50% water change today. Ammonia is now 2, Nitrite 0, Nitrate 5. I shall continue to keep the levels diluted over the next few days.

I've not checked my ph in some time so will dig out the kit and test it shortly.

The ammonia kit should be working as it reads 0 on all my other tanks.

For bio-media I have 2 sheets of rough sponge type stuff and a couple of packets of bio-max, neither of them ever look dirty as all the crap is collected in the first and second mechanical filtration baskets.

Kind Regards

Luke

[SBA]

if you do have a low KH doing water changes will help to replenish it and bring the pH back up.

if the pH is (was) really low then even at a reading of 5ppm the ammonia wouldn't be as harmful because most of it would be ammonium not ammonia.

again if it is the KH adding soda bicarb to your change water until it has a KH of around 4 dKH (or adding crushed coral / aragonite to the filter in a mesh bag) will help to stabilise it.

HTH
Ade

[lukeMH]

Did a test and ph was lower then usual at 6.8 (usually 7.12+)

I dont have a KH testing kit, I've never had anyone tell me to test KH or had a reason myself to need to know. To be honest I dont understand the whole ph crash / kh theory as to why my filter bacteria has been killed off. So I am going to have to do some reading up.

You are probably right about it not being so harmful as I really can't see any change in my fish behaviour whereas one of my other tanks I recently had a nitrite spike as the external filter jammed, and I could see straight away that the fish were not happy.

Kind Regards

Luke

[SBA]

well the reason to know the KH is so that you know how likely your pH is to drop.

the KH acts as a buffer for the pH, so that when you add acids to a tank with a high KH it is the KH that is depleted and the pH will stay the same (depending on how much acid of course). once the KH is depleted then very small amounts of acid will cause the pH to drop - sometimes by a lot and quickly.

as mentioned 4 degrees (or ~71ppm) is usually considered to be the minimum for a stable pH.

to put it in perspective my tap water has a pH of ~7.8 and a KH of 0 to 1. if i don't add bicarb then within a week of a water change the tank's pH will have fallen to around 6.5. the problem is that when you then add fresh water in turn the KH is replenished and the pH jumps back up. so i add bicarb to my change water to around 4dKH and my pH never fluctuates at all through the week.

and as mentioned the other problem is that at a low pH the nitrifying bacteria are far less motivated! hence the ammonia spikes.

HTH
Ade

[lukeMH]

I have found the problem, but what is the solution?

I am used to my tap water being 7.14 ish.

For some reason I didn't think of testing my tap water again until last night. I did test it and the ph of my tap water is currently 6.0!! So my water changes are infact lowering the ph instead of raising it :/

This could also explain the problem I am having in my other big tank. It is stuck in the Nitrite stage (After the filter clogged up for a short while) The nitrite levels are huge and 50% water changes daily and minimum feeding every 2 days has done little to reduce the Nitrite level.

Luke

[SBA]

firstly you need to know the KH, if that is low then adding bicarb / aragonite / crushed coral is the solution. this will bring the pH back up to around the levels you are used to with a bit of trial and error.

HTH
Ade

[lukeMH]

I have not managed to get hold of a KH kit locally yet so I still dont know that .... although I dont see how I am going to be able to change tap water which is 6.0 back into the 7.14 that it used to be.

The tank is not doing well it is stuck in the ammonia stage of the cycle and has been for 3-4 weeks now so I think it is beyond hope of re-cycling.

I am feeding the fish small ammounts every other day and doing 50% water changes to keep the ammonia levels low, but every test i do the ammonia has gone back up.

I have also added aload of extra bio media, which I soaked in 'cycle' before putting it into the filter, I have also done a few filter squeezings from my healthy axolotyl tank, but nothing seems to be encouraging the bacteria to grow.

[Scarlet]

Your LFS will be able to test for KH until you get a kit. I agree, it's very important to find it out in this case.

Does your local water company use chloramine insted of chlorine, do you know?

[Agostinho]

and as mentioned the other problem is that at a low pH the nitrifying bacteria are far less motivated! hence the ammonia spikes.

HTH
Ade
So... at low PH the bacteria are not active, but the ammonium will not become ammonia ? Is it possible that the situation will become self-compensate and everything is OK :confused: (my apology if this is a silly question)

[SBA]

at a low pH more of the total ammonia is relatively harmless (not totally) but there is still a proportion that is ammonia. it will still harm the fish, even if through long-term exposure at a sub-lethal level.

nitrification becomes compromised at a pH of around 6.5 and stops altogether at a pH of somewhere south of 6 so there would always be a (possibly sub-lethal) level of ammonia in water that acidic.

one problem would be that the water is highly unlikely to remain at a pH of 6 i'd have thought. most water companies increase the pH of their water one way or another to avoid acidification of (for one thing) copper pipes. once the pH of the tap water increases, the tank will follow.

also water with a pH that low must have a very low KH which means it will be prone to drop even more. if, on the other hand the pH suddenly rises (by adding some form of carbonate which should happen through water changes) and the nitrifiers have been 'dormant' for too long then you will get a period of high ammonia levels while the bacteria catches up again.

not made that very clear, but what it al means is that well buffered water with a KH of around 4dKH will avoid all the problems and will not have ongoing problems with ammonia IMO.

Ade

[SBA]

actually re-reading the original post another thought just occurred to me.

you say it's a mature tank of 2-3 years old and the bio-media has never been cleaned at all.

depending on what type of media you are using some of the pores can get clogged up with dead bacteria over time, and that can massively reduce the amount of surface area that the remaining bacteria can occupy.

it might be worth either: giving your bio-media a rinse in tank water (which you should really do every so often) to remove some of the gunk, and / or starting to slowly replace some of the old media with fresh (such as effisubstrat or the like).

just a thought.

Ade

[Agostinho]

also water with a pH that low must have a very low KH which means it will be prone to drop even more. if, on the other hand the pH suddenly rises (by adding some form of carbonate which should happen through water changes) and the nitrifiers have been 'dormant' for too long then you will get a period of high ammonia levels while the bacteria catches up again.

not made that very clear, but what it al means is that well buffered water with a KH of around 4dKH will avoid all the problems and will not have ongoing problems with ammonia IMO.

Ade
Thank you for the explanation Ade :thumb: . In fact, you have already made it much clearer. So... my water is hard water with PH8 and I always get the scale in the kettle and on the glass door of the shower cubicle / mirrors. Can I say that my water should have high KH :confused: (I am going to have it test this weekend).

[lukeMH]

I went to my LFS and he agree'd that the local water is all over the place at the moment, its acidic and almost 0 KH. He said to use powdered ph7 stuff. Any comments before I go and buy some?

Oh and the bio media is clean, its at the end after a hell of a lot of filter floss so it never gets dirty. It's not really 2-3 years old as when I setup a new tank etc I grab a handfull of biomedia from the mature filter to use in the new tank and replace the part I have stolen with new media, so it has been rotated round a fair bit. I have however not done this in some time, although I recently added a full box of new media which I soaked in Aquasafe

Luke

[SBA]

hi luke

don't use the proper pH type products or you'll never know what's going on with your water.

you can buy a tub of bicarb of soda for about 50p and it will do a better job. add it to your change water until it measures 4dKH or ~80ppm and then over the next few water changes your pH will become rock solid.

Agostino - phew, glad it made some sense! and yes, the deposits on your kettle / pipes / bath etc if hard and limescaley are caused by your hard water leaving behind some of it's hardness. boiling reduces the KH of water which is why kettles get so bad in hard water areas. in my area the water has no (or very, very little KH) and my kettle is as clean as a whistle.

Ade

[Agostinho]

4 dKH is enough? Water test showed that my water was 7 dKH and PH 7.5 (early morning water). But my Ph was always 8 before adding CO2. If my KH is so high, how can it be changed (by CO2 presumably) :confused:

[SBA]

co2 dissolved in water = carbonic acid which is what lowers the pH of water with injected co2.

4dKH is usually considered a good level to promote stability of pH (so if you are adding KH to the water there is no real need to go any higher than 4). 7 isn't high really, just about right.

Ade

[Agostinho]

Thanks Ade.

I just thought that KH 7 would have stopped PH change altogether.... after your explanation, now I think ... the PH change will only stop if the KH is, say, 14 !

Anyway, it is a good thing as I want lower PH. cheers

[SBA]

even with a KH of 17 you'd still get a pH swing when adding co2.

this page (http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm) contains an explanation and a calculator so you can work out desired co2 / KH / pH amounts in your tank.

Ade

[Agostinho]

This website has helped me a lot in understanding the KH, PH and CO2 things. Thank you very much :thumb: