Please help me stabilize and clarify my fish tank.

March 28, 2006 8:33 AM

I cannot stop my fish tank from turning cloudy. Please help, I've included some pictures inside.

Here's what my fish tank looks like a week or so after cleaning it with a gravel vaccum, changing 80% of the water, and installing a new filter (click each image for a larger copy):


I have a 20 gallon freshwater tropical tank, with a heater keeping the water between 78-80°F. I've had the tank for several months, but have always had this problem with cloudy water. It's gotten much worse lately, though.

I've got five little blue fish, two silver-dollar-like ones, one orange guy, a clown loach, and three little yellow guys. I used to have two snails, but they died. Perhaps relevant to the issue, the snail shells seemed to deteroirate over time in an unhealthy way. All of the plants are live, but I've gone through several. They seem to slowly turn translucent. The latest is that large plant - which is showing black splotches on its leaves now.

I've got an ammonia detector tag inside, which has never indicated a problem. I've got test strips for various stuff, and only ever see the nitrate go up a little, never to a dangerous amount. The pH is a little low, and I've never been able to get it up to 7.0 and have it stay there. For awhile I used pH adjustment drops, but lately have been trying this white buffer powder solution stuff. Still doesn't seem to help.

Please help me stabilize and clarify my fish tank. I'm not averse to paying for, let's say, a new type of filter (currently using the standard 4x3 carbon bag things), but I want to know what I need first. The local pet stores haven't been very helpful.

posted by odinsdream to pets & animals (19 comments total)

The layer of gravel on the bottom of your fishtank looks a little thick. It can easily trap dirt and make your filter less effective. Try drastically cutting down the amount of gravel you have and just leave enough to cover the bottom.
posted by Alison at 8:49 AM on March 28, 2006

is it getting any sunlight at all? even indirect sunlight (reflecting off of mirrors or glass) can wreak havoc.
posted by alkupe at 8:54 AM on March 28, 2006

How long has the fish tank been up and running?

Did you rinse the gravel before putting it in the tank?
posted by agregoli at 9:07 AM on March 28, 2006

How often do you feed them? We were having constantly-cloudy water problems* and after talking to our pet store, they said to stop feeding them so much. We went from feeding them a pinch twice daily to one large pinch every other day, et voila! Crystal clear tank water.

*20 gal., 3 dojo loaches, 6 clown loaches, 6 skirted tetras, 1 snail, 2 gouramis, 3 beaky things
posted by mimi at 9:07 AM on March 28, 2006

Sorry, I see you say you've had it for several months.

How often do you change the water? I'm hoping you're not doing an 80% change every week, for example.
posted by agregoli at 9:08 AM on March 28, 2006

PS: loaches really like a sandy bottom, it's easier on their strange little mouths and feeler thingies. They also really like other loaches, you might consider getting him a buddy or four.
posted by mimi at 9:09 AM on March 28, 2006

Feed only what gets eaten in 5 minutes, and yes, more than 30% changes per month is excessive.

pH doest sound horrible (a couple of your fish like a low-is ph) but this sort of thing just takes time. Usually the cloudiness is a bloom of bacteria that will eventually settle down as a tank establishes itself. This type of critter lives in the gravel rocks, and my experience has been that using an undergravel filter in addition to your carbon bagger will make for a more resilient tank.
posted by ernie at 9:33 AM on March 28, 2006

I think you don't have the bacterial cycle up and running yet.

From here:
While not exactly part of the cycling of the aquarium, it is worthwhile to realize that the "cloudy white haze" that develops in new aquariums (New Tank Syndrome) or after a major disruption in the aquarium is related to the nitrifying bacteria. When these bacteria are not present or their mature colonies are disturbed, a free-floating type of bacteria will quickly multiply to eat the available wastes in the water. While this is harmless to the fish, hobbyists find this incredibly annoying. In almost every case, simply waiting for the nitrifying bacteria colony to establish/re-establish will cause the cloudy haze to disappear.
posted by Kirth Gerson at 9:49 AM on March 28, 2006

In my experience, the test strips for testing water chemistry parameters suck. Get the kind with the little test tubes and droppers. They take a little bit longer but are much more accurate.

80% water changes seem a bit much. I change ~40% every two to three weeks, and that has been working well for me.

Are you keeping a fish tank log? Every time you test the water chemistry, write down all the test results, as well as everything else you do to the tank (water changes, fish dying, aquascaping) and what happens may help you sort out the cloudiness. In any event, it's a useful tool to keep track of things, because at some point you won't be able to remember all the details of when you added a particular plant or fish or so forth.

With regards to raising the pH, I've had very good results from taking a few Tablespoons of crushed coral (available at any LFS) putting it in the toe of a nylon, tying a knot in the nylon and dropping it in my filter assembly. (My tank is 55 gallons, so you'd need to adjust this downwards a bit.) The crushed coral brought my ridiculously soft water up to a much better pH. (my experience, and more discussion of raising pH, in this thread.)

Finally, while mimi is right that clown loaches are happier in groups, a 20 gallon tank is really not large enough to keep loaches thriving over the long term. One loach will likely be okay for a while but will eventually get stunted (full size for a clown loach is twelve inches) so if you can upgrade to a larger tank down the road, your loach(es) will thank you for it.
posted by ambrosia at 10:08 AM on March 28, 2006

I agree that the test strips are next to useless. I found that out after spending 20 bucks on a box unfortuately.

If you can find it, there is a product called "Stress Zyme" that I have used lots and lots of when I get the free floating algae in my tank this time of year (which looks like your issue, but green, not white) and it's a huge help. I buy smaller bottles then I linked to by the way! It's a way to boost the beneficial bacteria that kirth mentions.

We have a GREAT fish guy in town, and he suggests no more than 10% water change monthly. Of course, conditions sometimes demand something more aggressive, but for the most part, there is no reason to change more, if you are not overfeeding, etc. Good luck!
posted by Richat at 10:49 AM on March 28, 2006

A couple clarifications:

Sunlight: There are windows in the room, but otherwise the tank is in a shaded, dark location. Moving the tank is not an option.

Total tank life: I've had it for a few months.

Gravel: I got it in dry bags, rinsed most of it by accidentally starting with a leaking tank (which leaked only once I had it 50% full). So, most of it had been washed before, though not intentionally. Per mimi's suggestion, I'll try adding some sand and reducing the overall gravel amount (but it's so pretty!)

Food: I've been doing two pinches a day. I'll try mimi's reduction suggestion first, since it's awfully simple.

Water change: Usually I only do 10-20%, I did the 80% water change a few weeks ago in an attempt to erase whatever I potentially messed up. I did this after visiting the pet store and picking up a gravel vaccum. In the process of using the gravel vaccum, I picked up a huge amount of green sludge, so I figured I ought to start fresh (plus, using the gravel vaccum sucked out a great deal of the water anyway).

Honestly I'm still not sure after reading suggestions. I think I understand what the cloudiness is, now, thanks to Kirth, but why are my plants not healthy? What about the dissolving snail shells?
posted by odinsdream at 12:05 PM on March 28, 2006

Your plants may do better with a different type of substrate. I used Eco-Complete with good results. It's also fairly soft, so it's easier on the loaches' barbels. (I have three loaches myself.) Are you adding any plant food to the tank? I've had good results from using Tropica Master Grow and Seachem's Flourish line.

You didn't mention what size the snails were that died. Clown loaches like to eat snails, and even snails that are too big for them to gobble up can be harassed endlessly until stress does them in, and then the loaches gobble them up. Snails and loaches don't mix well in a tank, generally, so that would be my guess as to what happened to your snails.
posted by ambrosia at 1:51 PM on March 28, 2006

I am not an aquarist, but my wife has a 44-gallon freshwater tank that is always crystal-clear. She monitors the water quality very closely, using those test-tube kits ambrosia prescribed. She changes 40% of the water every 2-3 months. No real plants in her aquarium, though.

I would reduce the feeding to the amount they can eat in five minutes, as ernie said. I've heard the wife say this too. When she's away, she makes up little bags I'm supposed to use one of every day, and they are tiny amounts of food. Then just be patient. When the bacteria get going, you'll be amazed at how fast the haze disappears.
posted by Kirth Gerson at 1:52 PM on March 28, 2006

Many people with plant problems underestimate the amount of light they need. Investigate brighter options and your plants will love it.
posted by ernie at 5:43 PM on March 28, 2006

# Water change: Usually I only do 10-20%, I did the 80% water change a few weeks ago in an attempt to erase whatever I potentially messed up. I did this after visiting the pet store and picking up a gravel vaccum. In the process of using the gravel vaccum, I picked up a huge amount of green sludge, so I figured I ought to start fresh (plus, using the gravel vaccum sucked out a great deal of the water anyway).

Please keep in mind that I am speculating here, as I don't have enough information to provide you with a definitive answer.

How frequently do you apply treatments to your water? It is possible that you could be inadvertently disrupting the natural cycle within your aquarium. What type of treatments do you add, if any?

It is also possible that you are now experiencing what is known as a bacterial bloom, and you should expect your ammonia level to increase as the bacteria expire. You should monitor the formation of this equilibrium carefully, as the process could endanger the fish in your tank.

It's rarely a bad idea to add filtration to your tank. You might also consider a UV sterilizer, which can eliminate algae and other unwanted organisms. Finally, you might add an air stone to increase oxygenation and provide your tank with a nice visual touch.

On a related note, I assist in the operation of a forum that is dedicated to serious aquarium enthusiasts. I'm not looking to spam, but there are a number of threads about this problem in our Aquarium Discussion forum. Here, for example, is a very comprehensive article that explains more about bacterial blooms and their various causes.

Good luck with your fishkeeping endeavors!
posted by scoria at 10:46 PM on March 28, 2006

On a related note, I see a juvenile Oscar (Astronotus ocellatus) depicted in the left picture. That's going to grow into a somewhat massive fish (approximately 12 to 18 inches) with a wonderful personality. Many fishkeepers compare their level of intelligence to that of a dog or cat.
posted by scoria at 10:54 PM on March 28, 2006

I think what you're seeing there, scoria, is a (blood dwarf?) gourami.
posted by mimi at 4:28 AM on March 29, 2006

I also think that when you get the water quality right, you should get another Clown Loach. They're very playful, but don't get much outlet for that when alone. Oh, and it needs more cowbell Neon Tetras. A big school of them is a spectacle. Don't exceed the tank's capacity, though.
posted by Kirth Gerson at 7:41 AM on March 29, 2006

It's a gourami, as mimi said. Thanks very much for the link to your forums, though. That's going to be a great help!
posted by odinsdream at 8:17 PM on March 30, 2006