Oops. Help!

[Fishkeeper]

Awhile ago I replaced the sand in my tank with compost, which has worked out pretty well until a few days ago. I noticed an odd sort of rotten egg smell around the tank. (It might have been there awhile, I had allergies before and couldn't smell anything) Now, I knew this was bad, so I did an 80% water change. No more smell, until the next day. At this point I was seeing other bad things: most of my fish staying at the surface, pest snails trying to escape the water, and general signs of bad water. I was really concerned at this point, so I moved all the fish to a tank with almost all new water, as well as all the plants. They are all fine. The problem is that the old tank still smells like rotten eggs. Here are the things I have noticed:
Bubbles of rotten egg-smelling gas in the compost.
My African dwarf frog seems to REALLY HATE the bubbles. It freaked out if one touched it, especially if it was on the head.
STENCH!
Ammonia 3.5
A pump stirring the compost seems to help with the smell.
The compost may have had manure in it.
So, what do you all think the problem is? The compost is five inches thick, could this cause the problem? I'm pretty sure I need to remove some. How much? I don't really want to mess around in there too much. (it stinks worse than a roadkilled skunk!)

[ridgenesss]

if i were you i would remove the compost. there's no telling what decayed over time to make that. probably some horrendous bacteria in there. if you want you could use potting soil in place of it. since compost is made of decaying organic compounds high ammonia levels are most likely unavoidable.

[MLBfan]

3.5 ammonia is waaaaaaaay too high. Remove all the substrate. I would move your fish and clean the tank extremely well with hot water and vinegar or but a new tank.

REMOVE ALL OF IT!

[Fishkeeper]

I already removed the fish. Doesn't potting soil have chemicals in it?

[Aeonflame]

Compost contains way too much rotting organic material to be safe for a tank.

[ridgenesss]

I already removed the fish. Doesn't potting soil have chemicals in it?

potting soil has nutrients and minerals that are key to plant growth. if you dont use potting soil you could use regular substrate with root tabs or liquid ferts.

[MLBfan]

Don't worry about substrate right now. Just get those fish in a better, healthier tank.

[cbenner]

The substrate is anaerobic which is causing the rotten egg smell.That will produce hydrogen sulphide gas which will kill your fish.You need to use a substrate that does not pack down so densely and is not so deep so it alows some circulation through it.Maybe gravel.

[MLBfan]

Yes, use a gravel or aquarium appropriate sand, but right now just clean the tank then make sure the filter stays running in water (so as not to kill Beneficial bacteria).

[Fishkeeper]

Don't worry about substrate right now. Just get those fish in a better, healthier tank.
I've said twice I already removed them. I'll definitely remove the compost and replace it with potting soil.

[MLBfan]

I don't want to start an argument, but why do you want to use soil?

[Fishkeeper]

For the plants. I wanted the tank to be more natural. It sure looked good, but there was the small problem of it making my aquarium a septic tank :P

[mommy1]

Make sure you buy organic potting soil with no added fertilizers.

[MLBfan]

It could work, but I'd just use sand or gravel if I were you, I mean, how do you clean soil?

[mommy1]

Using organic soil is common with planted tanks. You don't clean it and it is capped with either sand or gravel, which you do clean.

[MLBfan]

Using organic soil is common with planted tanks. You don't clean it and it is capped with either sand or gravel, which you do clean.
I was unaware of that... anyway, I would still worry about the fish before gravel. What are the fish that were in there?

[mommy1]

I was unaware of that... anyway, I would still worry about the fish before gravel. What are the fish that were in there?

It could work, but I'd just use sand or gravel if I were you, I mean, how do you clean soil?

Then maybe you should not try to give advice in a topic which you are unfamiliar and stick with what you do have experience in and are familiar. Not trying to be mean, but this is a pet peeve of mine and how misinformation gets spread.
Of course we are all concerned with fish first. In this case the OP used a bad choice for substrate and we are trying to give advice on what type of soil should be used for a more natural and healthy environment for the fish.

[MLBfan]

Then maybe you should not try to give advice in a topic which you are unfamiliar and stick with what you do have experience in and are familiar.
Sorry, I shouldn't have gotten so deep into the soil discussion, you are right. I apologize.

[Fishkeeper]

I was unaware of that... anyway, I would still worry about the fish before gravel. What are the fish that were in there?
The fish are in a makeshift tank I set up. I have quite a few:
2 zebra, 1 blue, 2 leopard danios
2 celestial pearl danios (getting more after I clean up this mess)
3 1 1/2" cories
3 pygmy cories
1 African dwarf frog (not a clawed!)
1 large tadpole that is no longer a tadpole and was removed yesterday
2 small female bettas
1 killiefish
Is this too many for a heavily planted 20? CPDs and pygmy cories don't get much larger than 1/2"
long. And yes, in hindsight, compost in a tank = stupid.

[MLBfan]

answers in red:
The fish are in a makeshift tank I set up. I have quite a few:
2 zebra, 1 blue, 2 leopard daniosdanios should have one specie school, but I have also heard that they are fast swimming, I don't know if they work in a 20 or not.
2 celestial pearl danios (getting more after I clean up this mess)maybe you could just have a school of these danios instead of the others.
3 1 1/2" cories
3 pygmy coriesInstead of the 2 different corie schools, how about just the pygmy in bigger #s
1 African dwarf frog (not a clawed!)
1 large tadpole that is no longer a tadpole and was removed yesterday
2 small female bettasmay not work w/ danios, I believe they are slow moving (unlike danios)
1 killiefish
Is this too many for a heavily planted 20? CPDs and pygmy cories don't get much larger than 1/2"
long. And yes, in hindsight, compost in a tank = stupid.

[Fishkeeper]

Thanks for the advice. This setup was working just fine fishwise. All the different species of cories school together. The larger danios all school together as well. The CPDs mostly stay to themselves, which is why I want a few more. The female bettas do just fine. I forgot about my female guppy that schools with the danios, and my tiny sparkling gourami that thinks it's a female betta. And scratch the killie, I just found him dead for no apparent reason:scry: He was fine a few hours ago. I'm guessing whatever toxins were in the compost damaged his gills too badly.

[DeadSulphurhead]

I don't see why you chose compost for a natural look? There isn't compost on the bottom of any water bed I've ever seen. Experimenting with something like that you should of definitely researched beforehand. Why not get a fine substrate like sand that is the same colour as the wet compost, and use fertz?

As for the stock, is it a 20g long or tall? and what's your filtration? They are all compatible aggression wise, with the possible exception of the killi. There's a ton of different killis, some ranging from under .5" to over 3". Just like size, temperaments vary a lot too. Certain killis can become nasty and nip fins, if not kill smaller fish when they hit maturity. I had a golden wonder killi that would constantly attack a weather loach that was 10x it's size! I'm guessing either because of it's colour or it's shape?
I'd also recommend just getting more pygmys instead of mixing. Sure mixing corys will get along, but never as well as with their own kind.
You should get atleast 6 CPDS, preferably 10. They are fairly delicate to many factors, and the stress from under schooling can have a big impact on CPD stress. Expensive little guys to not make them happy as you can.
Getting more also depends on your filter and it's GPH

[Fishkeeper]

It's kind of a long story why I chose the compost. Basically I like the look and the plants like it as well. Plus, before it started stinking my cories loved it. They were just goofing around in it like kids in a sandbox. Also, I researched the compost. From what I read, organic soil is safe, and compost was the only organic soil the store had. I never saw anything about not using compost. The killie was a Golden Wonder. He was gentle with other fish, and never acted aggressive at all. The pygmies often play with the CPDs as well as the other cories. The filtration is a HOB filter meant for a 30g tank, plus I have an airstone. I also am going to put a whole bunch of plants in there. A fish store near us is closing, so when I can I'm going there for a bunch of plants. I'm thinking 5 more CPDs and another pygmy? Like I said, the pygmies act just like the CPDs sometimes. Heh, those CPDs are FEISTY! I see them chase the other danios who are five times their size.

[Fishkeeper]

Well, the old tank is emptied and scrubbed. I have sand to put on top of the dirt, (keeps it from getting stirred up), but no dirt. Found a garden center 45 min from us that carries potting soil with no chemicals or manure or nasty stuff, now just need to convince Dad to take me. Hopefully we can stop by a pet store on the way home and buy more plants, and maybe a new light.

[Fishkeeper]

I bought a HUGE (6"!) Java Fern, some hornwort, a chunk of driftwood, and a plant that was labled 'Amazon Sword' but on closer inspection is way too stiff for an aquatic plant. The mock sword will probably be placed with just the roots in the tank, or it might go into my vivarium. Driftwood is soaking in a bucket. I didn't get the dirt, probably will tomorrow.

[Fishkeeper]

No fixed date on the dirt. Me id getting mad.