I purchased an aquarium for my kids a few weeks ago and I need some help. I seem to have a huge bacterial bloom that keeps clouding the water and I'd like some advice as to how to handle it.

Some info: It's a new tank, 5.5 gallons with a small filter. I have one betta fish and four tiny danios. I planted five small aquatic plants when I first started the tank. It's my first aquarium, but I did read up on the nitrogen cycle and have only been adding purified (not tap) water. The pH is 7.0 and my ammonia levels test as 'low' as I've been careful not to overfeed. I've done 20% water changes once a week which has knocked the cloudiness down but not out.

I'd really like to have my crystal clear water back. Any suggestions?

P.S.: I'd really love to see what tanks & fish other members have!


Here's a pic of my tank:

It sounds like Calilasseia would be the one to ask here. All I would say though is that cloudiness does not in itself necessarily indicate anything that's a potential health risk to the fish if that's what you were worried about, although I can understand why you'd want the water to be clear for aesthetic reasons.

You've added fish too early. Your aquarium is still cycling.

The cloudy bacteria boom is your cycle doing what it's supposed to, it's just not ready yet. It will go when your filter is fully cycled so for now I'd be making more regular water changes.

What are your ammonia, nitrite and nitrate readings?

This is my tank, I don't actually use a filter, I'm using a complete different method but I don't want to confuse things

My water is a little cloudy as I've just moved a few plants around.

Thanks for the replies. I'll test my water later and post the results. I've read about tank 'cycling' and my fish look healthy, but how cloudy does the water get before the cycle ends? How long does the bloom last until it clears?

BTW, nice tank Paul. Is it purely for the aquatic plants or do you keep fish as well?

It shouldn't last too long. It will clear up on it's own fairly soon, the extra water changes are just to keep your ammonia/nitrite/nitrate readings down while the cycle completes. If it's been set up a few weeks maybe a week or so at a guess.

If you're still having water clarity issues once cycled filter floss is AMAZING at cleaning up your water. It's cheap too.

Just plants as I'm waiting for enough plant mass to handle the bioload from the fish before I add them.

This is basically what I'm doing:

http://theaquariumwiki.com/Walstad_method

Dont own one but asked a guy at work who does, he said-
A) Dont have it in direct sunlight. That causes algae blooms.
B) There is a fish you can get that acts like a cleaner. They suck the algae off the tank walls and even sucks it off the little pebbles in the tank.
C) Take a sample of water to a good Aquarium shop. They can test it for you.
Good luck.

Thanks for the reply, Doug. My 'problem' is a bacterial bloom, not algae. My tank is not exposed to direct sunlight and the bloom is cloudy-white, not green.

I did find a local pet store that will test my water for free. I bought a few shrimp to eat algae, but the betta killed them all.

AlohaChris wrote:Thanks for the reply, Doug. My 'problem' is a bacterial bloom, not algae. My tank is not exposed to direct sunlight and the bloom is cloudy-white, not green.

I did find a local pet store that will test my water for free. I bought a few shrimp to eat algae, but the betta killed them all.

Sorry mate.
I'll see what he has to say about bacterial blooms.

I want to know more about the OP's setup:

What's that light source?
Is it heated?
What sort of filter is in there?
How deep is the substrate? What is in the substrate?
Are those plants rooted to wood?
How is the water for water changes "purified?"
Why have you chosen not to use tap water?

The answers to these questions may help reveal the source of your bacterial bloom.

ScholasticSpastic wrote:I want to know more about the OP's setup:

All right.

ScholasticSpastic wrote:What's that light source?

12 small LED bulbs that come in the combined filter/fountain/lights with the tank.

ScholasticSpastic wrote:Is it heated?

Yes. I've got a small 25W stick heater in there for the betta.

ScholasticSpastic wrote:What sort of filter is in there?

A small combined filter/fountain/light that came with the 5 gallon tank. It's a Fluval Chi model. It has a white filter pad and a black sponge that lies behind that.

ScholasticSpastic wrote:How deep is the substrate? What is in the substrate?

Off the shelf black aquarium gravel. I washed it carefully before adding it.

ScholasticSpastic wrote:Are those plants rooted to wood?

No, they're shoved in the gravel. They are Dracena, I think, some kind of sword plant.

ScholasticSpastic wrote:How is the water for water changes "purified?"
Why have you chosen not to use tap water?

It's bottled from the market - purified by reverse osmosis (not distilled). It's pH is acidic, which I correct before adding it with "pH Up" from the fish store. I didn't use tap water because what I read on the interwebz said it has chlorine that's bad for the fish.

Dracana isn't an aquarium plant, it's terrestrial. Not your fault, the shop probably didn't know either. It will rot eventually and pollute your water. If you want an easy to grow plant get some java fern or anubias.

Reverse Osmosis water should be around ph 7, neutral Ph and would be fine for Danios and a Betta. If I were you I wouldn't use Ph up. Messing around with Ph is more hassle than it's worth and for the fish you're keeping not needed.

There's one issue using RO water, it strips the water so well it's actually not ideal for fish unless you replenish it with remineraliser.

Tap water has chlorine and in some cases chloramine but you can treat it with dechlorinator, which is what most people use. RO is really only used in marine aquariums or for people who wish to keep delicate, soft water fish like discus.

Thank's Paul. I'll pull the plants and see if that doesn't help. Here's a pic of the type of plant I have:

The Walstad thing looks appealing, but a lot of work. I'm trying to strike a balance between not being a noob who quits at the first sign of difficulty and letting the box with fish consume my life.

Yep, not an aquarium plant!

I'm not sure I'd advise the walstad method unless you're a fish geek like me. It's basically recreating the conditions of a pond.

AlohaChris wrote:

ScholasticSpastic wrote:I want to know more about the OP's setup:

All right.

ScholasticSpastic wrote:What's that light source?

12 small LED bulbs that come in the combined filter/fountain/lights with the tank.

This is not the issue because it's a bacterial- rather than an algal- bloom. But it might become an issue later if the wavelengths of light you're getting from the LEDs are off. Dunno how much work has gone into making LEDs suited for promoting vascular plant growth.

ScholasticSpastic wrote:Is it heated?

Yes. I've got a small 25W stick heater in there for the betta.

Excellent! A lot of people labor under the misapprehension that betas don't require heaters. They can often get by without, but they tend to get sick more often that way.

ScholasticSpastic wrote:What sort of filter is in there?

A small combined filter/fountain/light that came with the 5 gallon tank. It's a Fluval Chi model. It has a white filter pad and a black sponge that lies behind that.

I tend to instinctively mistrust every product which refers to "chi." I was unable to find information about how efficiently this model of filter increases effective surface area of the tank. This is essential for gas exchange for your danios and may help control unwanted bacterial growth as well. If you don't see appreciable disturbance of the water surface by your filter system, consider adding an airstone and pump to the works. I would not recommend a powerhead for a system that size with a beta in it.

ScholasticSpastic wrote:How deep is the substrate? What is in the substrate?

Off the shelf black aquarium gravel. I washed it carefully before adding it.

Gotcha. Good! It looked a little sparkly in the picture and I was concerned it might be mostly those glass pebbles which so many people like to put in beta tanks. Are you vacuuming this substrate when you do water changes? If not, consider obtaining a small-diameter siphon and pulling out some of the mulm when you do water changes. Go small-diameter so you have time to get your clean on before you've taken out all the water you ought to.

ScholasticSpastic wrote:Are those plants rooted to wood?

No, they're shoved in the gravel. They are Dracena, I think, some kind of sword plant.

This is my number one suspect. Anubias, java fern, or cryptocoryne are all plants I've had success with without mucking about with an over-elaborate setup. You can grow anubias or java fern rooted to a piece of driftwood for easier tank cleaning. It also tends to look really cool.

I don't know how you feel about snails, but I'm a big fan of malaysian trumpet snails when I do planted tanks. They burrow around the gravel during the day and can help keep dead zones from happening. They tend only to eat dead plant tissue and other detritus, leaving healthy leaves alone. But take care. If you once decide to keep trumpet snails in your tank you will be stuck with them until you completely empty and thoroughly clean and sterilize your tank.

ScholasticSpastic wrote:How is the water for water changes "purified?"
Why have you chosen not to use tap water?

It's bottled from the market - purified by reverse osmosis (not distilled). It's pH is acidic, which I correct before adding it with "pH Up" from the fish store. I didn't use tap water because what I read on the interwebz said it has chlorine that's bad for the fish.

Dechlorinator chemicals are cheap and easy to use. You can avoid increasing water hardness over time by using distilled water to make up for evaporation and then using de-chlorinated tap water for actual water changes. If your tap water parameters are acceptable for your livestock you will often tend to have a more stable tank using tap water. Any time you must manually adjust a parameter you introduce opportunities for variation. Keep in mind that pH is a logarithmic scale. Small errors in measured pH can be large for the occupants of your tank.