Tank Not Cycling

Hi, I actually joined the site ages ago because I was thinking of getting back into fish. I decided I didn't want the constant responsibility in the end.

Until my parents decided to buy my younger brothers one of those cheap aquarium set ups from Aldis/Lidls. So guess who ended up having to set it up?

Anyway, there's something gone wrong with the filter cycle and I can't quite figure it out.

Did three weeks fishless cycling with just fishfood. Then I let them buy fish. They got 3 zebra danios and a bronze corydoras (which they weren't supposed to get, but anyway). Tested the tank after a few days and the toxin levels had gone up, but nothing that I found too worrying at that early stage. The comparative levels of ammonia/nitrite/nitrite showed that the ammonia was being broken down.

Then they started to overfeed the fish which sent the toxin levels rocketing before the filter was fully cycled. I did a bigger water change than usual and gave out to them.

Next time I came to check the tank and do a water change the ammonia levels were quite high but there didn't seem to be any nitrite or nitrate. I wasn't quite sure why that would be.

Then it occurred to me that the filter may have gotten completely blocked with food and killed all the aerobic bacteria. So I put the filter sponge into a bucket of tank water and shook off all the food slime that had become attached to it.

The ammonia levels didn't go down and the nitrite/nitrate levels didn't go up at all.

Then it occurred to me that there was still uneaten food hidden somewhere. So I took the plastic plant thing they had in the tank and washed it under the tap. It was filled with decaying food.

But the ammonia levels still remained at the pretty much the same level. Still no sign of nitrite and nitrate.

They ammonia levels have been at around 1.2 mg/l for weeks now, in spite of regular water changes. I've been using ammo-lock and luckily the water's naturally neutral so the fish seem ok, but I can't figure out what's wrong.

I thought maybe it was the cheap filter supplied with the tank. I found out that it was a Via Aqua 302 power filter, which only seems to get sold in the US. I don't think it's big enough for the tank (24x12x12) but it still probably should be working at some level.

I bet the first thing you're thinking is that I haven't been dechlorinating the water, but the drinking water comes from the ground. Although that makes me wonder if the ground water is contaminated with something that's killing the bacteria. Or whether the ground water is inoculated with some other kind of bacteria and they've taken over the filter. Wouldn't surprise me since the house uses a septic tank and they'd be full of extremely hardy bacteria.

I almost feel like telling them to just buy a Fluval U2, but if it's not technically a filter problem then what's the point?

So any suggestions?

What media is in the filter?
If it is ust a small block sponge, the filter will very slowly adjust to amonia spikes from adding fish, over feeding, possibly to a point where it cant keep up with the amonia hence no nitrites or very little compaired to amonia

mark

F.w.i.w., I have one of the bigger lidl/aldi tanks fora while now. The original filter was a clone of an Ehiem 2010. I added a U2+, as the 2010 clogged easily. The combination of both works extremley well, just keep the fine/carbon sponges out of the fluval, and clean the sponge on the 2010 weekly. In your case, try to show your brothers the s..t on the foam and explain that it's actually food that hasen't been eaten...
Also, have you used something like safe-start to seed the filter?

Just wondering.....what are the fish doing? are they dying?

What about other conditions? eg pH, hardness.

My opinion on ammonia test kits is if it shows any sign of ammonia, then something is wrong with either the water or the test kit. Once you get a positive ammonia reading on the test kits, then graduations above that almost become irrelevant as the water is already suspect.

The actual process and science of this is too complex and involved to go into here, but briefly (and using generalisations)..

The nitrosofying bacteria (the ones that convert ammonia to nitrites) are generally free swimming and don't rely too heavily on the filter material itself. They do, however, require a good oxygen supply....and that is where good water circulation comes in (the action of the filter or an air pump).

Under acidic conditions, the toxicity of ammonia is lessened because it is tends to exist in the form of ammonium.
Ammonia toxicity increases in alkaline conditions because it exists as ammonia.

The nitrifying bacteria (the ones that convert nitrites to nitrates) are generally substrate bound (although some will also act in the free swimming state), and require the media in the filter itself upon which to live.
They require a good oxygen supply.
If the filter is blocked then they tend to die quite quickly.

Of the 2 types of bacteria, the nitrifying (on your filter material) tend to be the slower growing and are much more susceptible to changes in temperature, pH, oxygen, and various poisons.

But even if these died off then you would still expect to see nitrites unless something has killed off the nitrosofying bacteria.

I wouldn't necessarily suspect the tap-water supply and the linked septic tank as being the first port of call for investigation (although you can never rule that out).

Overfeeding?? My first guess.
You say a clogged filter? that will lessen water movement and oxygenation.
Test kit error if fish are looking good? maybe another guess
Irratic water conditions? eg pH swings would be something that needs looking at at that wlll kill the bacteria
There are a few other things as well. There do exist some other things where the water cycle itself will act to kill itself off....but we won't go into them here (yet anyway).

ian

Fish seem happy, strangely. Tap water is neutral, so some of the edge is probably taken off the ammonia. Unless it is in fact the test kit that's not working. Will pick up a new ammonia kit tomorrow just to check. It's a Nutra-fin Ph/Ammonia/Nitrite/Nitrate combined kit. It's also not past its use by date.

The filter is extremely crude, with just some nondescript sponge. I forgot to mention that I gave it a more thorough squeeze last time I checked it. Something I would probably have not done if I thought it was working properly. What came out stained the water milky yellow.

Fish aren't being overfed as I took away the fishfood and started feeding them myself until the tank stabilised. That hasn't happened so I'm still stuck feeding them.

I regret not trying something like safe-start now. I read somewhere that they weren't proven to be effective and my fish knowledge comes from before they were widely used. Might pick up some tomorrow just to see if it has any effect.

I wonder if it could be a combination of things, like poor flow through the filter sponge, low oxygen content in the water and the shock of all those water changes to try to bring the ammonia down. Still, I'd have expected to see some trace of nitrite or nitrate even so.

Fish are often a good sign of ammonia.

What's the pH and Hardness? is the pH stable?

There are a number of things that will inhibit the bacteria. But is this happening in this case?
and if so, what?

Carbon disulphide is a well known inhibitor of nitrosofication (ammonia to nitrite).
It may also exist with a yellow smelly (radishes maybe...for anyone who eats them things) compound called carbonyl sulphide (especialy if some oxygen is present).

I'm just speculating of course (as we sometimes do at this time of night).....but if your fish are healthy then maybe think about something more obvious eg the test kit again.

You could always try a zeolite ammonia remover if you are really worried about your ammonia, but then that may hamper maturing the water.

ian

Finally I get time to post an update

I bought a second test kit to confirm that the original ammonia levels were accurate. The API kit made the ammonia levels seem even worse. Almost ridiculously bad in fact. It made me wonder if there was more than just the fish producing ammonia in the tank.

So I pulled out that horrible plant thing that had contained so much food before. I put it in a bucket of water and shook it out. Then I emptied and refilled the bucket. Shook it out again. Emptied and refilled the bucket. Shook it out again...you get the picture. There was more decaying food in the plant than had ever got sucked into the filter. So much so that it made me wonder if objects underwater can build up an electric charge (even though I'd assume water immediately draws away any charge). I decided not to put that ornament back in, shockingly. The food must have been there for weeks and weeks too

I'm waiting to see if the ammonia will go down to zero. Either way I should probably replace the crappy filter. What would people recommend these days? Fluval, Aquaball or Tetratec IN?

Take a look at external filters they are not that expensive and would be much better compared to internal.
JBL or Tetra are pretty good.

I'd definitely go for an external for my own tank. I'm just sceptical whether an external filter will be worth it for a 24-12-12 tank that probably won't contain anything more exotic than danios and a few bronze corydoras.

Plus, knowing my family, the filter is actually safer in the tank.

Oh and I forgot to answer that pH question from earlier. The water in the tank and at the tap had pretty much the same pH reading last time I checked. The soft side of neutral, about 6.8. Although the hardness has always been harder than you'd expect from that pH reading.

Hi,

Your problem is simple- Ammolock.
When u use it it locks the ammonia together rendering it non-toxic.
Testing for ammonia after using ammolock will often give u false readings.
Always look at your fish.
A few water changes will sort it, leave your filter be.

Cheers,

Steve

Just found this thread and I see that Steve beat me to the answer.

Ammolock, simple as that.

hi theo
unfortnately i bought one of the same tanks off aldi at christmas and found the exact problem with trying to cycle it, 3 weeks and the tank was all over the place, Although i havent read the answers from the rest of the lads i think you answered the question to your problem in your first post THE FILTER, The filter is way to small to deal with even a small load, after three weeks I switched to a fluval U1 and low and behold a two days later i started my ammonia was dropping and the nitrite started to show.

PS there not that bad a tank for what you pay, just crappy filters

Bats:)

Update time.

Stopped using Ammolock a while back for those very reasons. I have a feeling that won't offer any simple solutions though. Hopefully I'm wrong.

I knew the filter was undercapacity, but I didn't know I'd have been better off never turning it on at all. It might actually have worked if I'd added just a little polyester pad to stop the sponge getting blocked. I hadn't realised how coarse proper filter sponge was till I saw what was being used in the proper models.

I added a U2 to the tanks over a week ago. Added some Nutrafin Cycle. Then heard that was useless. Tried some Tetra SafeStart, just to see if that changes anything. Have seen some signs of Nitrite and Nitrate, but they've been awfully mild. If that doesn't pick up, I'll look into getting an infusion from the pet shop that they got the fish in, although that's over half an hour away. The nearer ones aren't well kept enough imo

the use of organic aqua to set up a new tank will bypass all of these cycling problems. which is good news for the budding fishkeeper not to mention the fish.
it seems to work by instantly converting ammonia to a gassier form of nitrate while bypassing the nitrite stage altogether. the use of an airstone expels the nitrate from the water making the water perfect for even the most delicate fish. this stuff works instantly and fish can be added as soon as water is warm enough.
i cannot reccommend organic highly enough for beginners. the pluses are an instant healthy aquarium and happy stressfree fish. even the biggest fishkiller of all overfeeding is somewhat less dangerous.

Thanks Derek- I couldn't have said it better myself!!
To finish the ammolock discussion, if it has been used at all it will be present for a long time as it is very hard to remove locked ammonia from any system without lots of water changes or the addition of zeolite. It has absolutely nothing to do with the performance of your filter.

As i said earlier had the exact same problem and didnt use ammonia lock,if the ammomia levels are that high ammonia lock wont work anyway