Is my aquarium overstocked?

Question

It is a 60 litres (15 gallons) one.
It has:

* 5 neon tetras

* 7 guppies

* 4 glass catfish

* 2 kissing gouramis

* 1 pleco (small)

* 1 platy (very young, was a fry 2 months ago)

* 1 redline torpedo barb.

The nitrite level was always zero, the water is matured with filter bacteria and everything was ok. But recently I get nitrite levels going very high after a 2 days 30% water change...I even change the active carbon foam in less than 4 weeks...I use a gravel cleaner, and for some reason the bottom gets full of poo sometimes, out of nowhere! Is the fish/litres ratio too bad?
It is 4 months already so it is not a new one...and I didnt have any nitrite problems till recently. Also the fish have been added gradualy and I havent added any recently.

Answer 1

As others have told you, you are desperately overstocked. I like how the one person gave you potential sizes for the fish, too (saved me the time to look up everything to make sure).

Word to the wise, you want to be looking at nitrates, not nitrites. Nitrites should always be at zero if your cycle is working properly (it's the second part of the nitrogen cycle); the same goes for ammonia. Nitrates, on the other hand, are the last stage of the nitrogen cycle and are always present in a healthy tank. Nitrates should measure at no more than 40ppm, though less than 20ppm in more ideal.

You should, in a healthily stocked tank, only have to do between 20-40% water changes every week. With this tank and with all the fish, I'd suggest a 20% change every three days or so until you get a larger tank (you will need a larger tank - it simply isn't optional if you wish to keep all of these fish).

Also, you don't need to change out the carbon filter as often as you are. Carbon is only necessary to remove odors (which, if you do your water changes as often as you should, you should never have odor problems) and to remove medications. That's it. I tend to keep my filters in the tank until they start to fall apart. I just rinse off the poop and gunk every two weeks or so and pop it back in.

And it's normal to pull poop out of your gravel - you fish poop, and it has to go somewhere when it doesn't get sucked up into the filter. That's one of the reasons why you should clean your tank more often.

EDIT: Looking back, you don't even have a good mix of fish in that tank.

Neon tetras are sensitive to water parameters - they will show distress before all of your other fish when your water is "off". The are peaceful fish and cannot defend themselves well against aggressive tankmates. Read the following link for minimum requirements for your neons. http://www.liveaquaria.com/product/prod_Display.cfm?pCatId=1097

Guppies should be kept in a 2:1 female to male ratio. Some say they require brackish water, but I don't have any of mine (including the fry born last Thursday) in brackish conditions. They are also peaceful and cannot readily defend themselves. Read the link for more info on care. http://www.liveaquaria.com/product/prod_Display.cfm?pCatId=1045

Your glass catfish will grow to about 4 inches each, and are also peaceful. Read link. http://www.liveaquaria.com/product/prod_display.cfm?pcatid=2519&N=0

Kissing gouramis are classified as semi-aggressive fish. They grow to 8 inches, need a minimum of 30 gallons. http://www.liveaquaria.com/product/prod_Display.cfm?pCatId=968

Common plecos grow to be huge and need a minimum of 125 gallons each. Also, they tend to go after smaller fish when they run out of food. See link for different plecos, and read up on care. http://www.liveaquaria.com/product/scateg.cfm?pCatId=837

Platies are community fish, and should be kept in groups of at least four. However, they are livebearers and should be kept in the 2:1 female to male ratio as well. They are also peaceful fish. Read link. http://www.liveaquaria.com/product/prod_Display.cfm?pCatId=1067

Barbs are commonly semi-aggressive fish, and should not be placed with community and peaceful fish. However, this barb is a peaceful barb. The downside is that they need a minimum of fifty gallons and will grow to be 4.5 inches. Read link for more. http://www.liveaquaria.com/product/prod_display.cfm?pcatid=2217&N=0

Answer 2

Normally I'd say saying if you are over stocked is more complex that just how many fish are in you tank. The neons, and guppy alone would likely put you near the limits of your tank. Normally the rule of thumb it's one inch of fish per gallon for slim bodied fish. So with this rule you have x2-x5 your tanks capacity. (Depending if you count current or adult sizes.) You've got more fish than my 30 gallon tank that I feel is pushing the limits of it's bio-load, and I've got much better filtration than you.

You can reduce the nitrite levels by adding more filtration. For example adding an undergravel filter, or adding a box/corner filter. This might allow you to safely have everything other than the Gourami, and pleco. Provided you are good about weekly water changes, gravel vacuuming, not over feeding, and monitoring your levels.

Note that changing the carbon filters of most power filters is a double edged sword. Many power filter only have a single filter media with the carbon in it. This forces you to choose between good biological filtration, or chemical filtration. Bacteria that convert ammonia, and nitrites take ~2-3 weeks to populate the filter media. By which time you're starting to use up your active carbon.

This is why a dry/wet wheel (biowheel), or multiple filter media are better. For example in one of my tanks that is in theory over stocked. I have a power filter with a biowheel, and 2 filter bags. I replace only one of the filter bags once a month. (The other I've slit open at the bottom and removed the carbon.) My only problem in this tank is nitrate build up.

Answer 3

Way overstocked...the kissing gouramis will get to 12" each, they need at least 55 gallons. Your pleco, though small, may also get quite big (if it's a common pleco he'll get 18"). The red torpedo barb will get about 7-8". The glass catfish will probably get way to big too. I'd take these fish back to the store, and keep your neons and guppies. Maybe get some cories for the bottom level, and you're fully stocked.

Your nitrites spiked because your bioload is way too big. Get rid of the fish I mentioned, let your tank settle, and then add the couple of cories. 15 gallons is not much to work with. If you really want a gourami, settle for a dwarf gourami, the other species are all too big. Good luck and I hope the fishies make it.

Answer 4

You know you are over-stocked when you do a gravel-vac and you get an ammonia spike so bad that you loose fish. I haven't lost a fish to ammo since I first started this hobby, so this is my first time loosing fish to a gravel vac. Twenty gallon with half a dozen black skirt tetras and (was) five Buenos Aires tetras. Already lost two of them. Careful with those gravel vacs, they can be a wake-up call!

If I can give anyone advice here, I'd say to use an ammo-lock product to change the water after a gravel vac.

Take back about 6 of them or risk killing them from ammonia.

Answer 5

Yes, you have way too many fish in there. You can only have 1 inch of fish for each gallon of water. So if you have 7 fish that are about 2 inches each, that would be the maximum for that tank. The guppies and tetras will each get about 2 inches or more so that should be it, and maybe keep your pleco for algae. So 7 fish and your pleco is more than enough. Anything more is way too much.

Answer 6

I would say you have too many also. Rule of thumb for your tank would be 15 inches of fish, and you have more than that. Sounds like your filter cannot keep up with the # of fish. I would get a filter for a 30 gallon tank(even though yours is only 15) so that more water is cleaned per hour, and NOT add any more fish. I'm glad to hear you are testing your water though! At least you can keep on top of problems! :-)

Answer 7

yes,your OS
get rid of the glass fish,the gouramis and the pleco(probably common which need aboiut 125 gals each)
then you will be ok as long as you get rid of the fry.

Answer 8

I agree with the 1 inch of fish for each gallon rule, I have a 40gal tank that would be overstocked by that rule, but the filter is designed for a 100gal tank and the biological filter is overkill for the size tank i have. I would say get a larger filter one for a 30-50gal tank with a good biofilter because your tank has a large bioload in it. You should be okay if you get a bigger filter, just quit adding stuff :-)

Answer 9

The general rule is one inch of fish per gallon in your aquarium. So, depending on the size of your fish, you may or may not be overstocked. Did you make sure to treat the new water you added after the water change? Sometimes, adding untreated water will cause a spike. Go to the pet store and get a nitrate reducer, and see if the water balances itself out. Good Luck!

Answer 10

yah its overstock keep only 8 to 10 fish if its over then lots of chance of infaction any they die faster