I'm at my wits end with green water in my 10-gal freshwater tank. No matter what I do, it comes back or never goes away.

The tank had been fine - crystal clear and no problems for about a month. I was doing weekly 2-gal water changes and gravel vacuums, and all was going well. Fish in tank:

6 assorted tetras
1 neon fish
1 yoyo loach

Lighting: The aquarium gets no direct sunlight but some indirect that comes in through closed blinds. There is a betta in the same room in a 1.7 gallon tank that has no issues with algae at all. The aquarium light is only on when we're home, maybe 4 hours on weekdays and 6-8 on weekends.

Then we a started to get a bit of green algae growing on decorations, so we picked up a dwarf pleco and amano shrimp to do the housecleaning. They cleaned the entire tank overnight

Now here's where I'm sure I screwed up. As a novice and newbie to the hobby, worried that the algae eaters wouldn't have enough to eat, so after a few days of no new algae growth, I tossed in an algae wafer.

The wafer didn't go anywhere. The shrimp cruised across it a few times and nibbled, but the pleco seemed to ignore it. A few of the tetras nibbled at the wafer, but after a day or two I pulled it out, about 3/4 of it still unmolested.

Then I read about putting veggies in the tank, and thought that would be fun. I tossed in a zucchini slice, thinking the fish would love it. Again, the shrimp stole a few seeds, a few fish nibbled at it, but it didn't disappear, and after a day, I removed the slice from the tank. All seemed ok.

A few days later, I noticed that the pleco was acting strange. he was staying near the surface and ignoring algae growing on decorations in places he had had no problems cleaning before. a few days later, the pleco was dead on the gravel, and my tank began clouding up.

I have since added a new dwarf pleco who never stops eating - he is literally always sucking on something and never in the same spot twice. I am beginning to think my first pleco may have been sick.

I have tried the following:

flocculant/water clarifier: Worked for three days, then re-clouded.

Reduced feeding to once every other day

Switched from treated tap water to distilled water: Turns out I have hard, high-pH tap water.

Daily 25% water changes & gravel cleanings: never gets rid of the fill cloudiness, always returns

Put a moss ball in the tank to try and steal nutrients

50% water change with water clarifier: Only got slightly better, and quickly devolved back to green water.

Changed from an Aqueon 10 to an AquaClear 20 filter: no change

My latest solution:

Algone: Placed in filter, seems to have leveled off the bloom and stabilized or slowed its growth, but water is still not clear.

Water temp is around 76°

I'm at my wits end. I am hesitant to use the clarifier again, after reading how it can damage gills. The fish seem healthy and happy and have weathered the storm of my attempts with seemingly no ill effects (aside from the first pleco). The Amano shrimp has molted once, and seems to be doing fine.

I want to avoid using a algaecide, as I don't want to hurt the shrimp or the moss ball, but I'm not morally opposed to chemical use. The aqua store mentioned an organic algaecide that they said would not affect the shrimp, but it was expensive for a 10-gal tank.

I bought a testing kit and have kept track of my water readings throughout. All readings have been good throughout this ordeal. I did 25% change & clean today, and tested the REMOVED water and got as follows:

pH: 7.6
Ammonia: 0 ppm
Nitrite: between 0 and 0.25 ppm
Nitrate: 0 ppm

The removed water is green.

The only thing I haven't tested lately was phosphates, but early in my algae bloom problem, my local aquarium store tested the phosphates and they were fine.

As I said, I'm at my wits end here. It would seem I've got good water, clean fish, an active cleanup crew, healthy maintenance, and an appropriate amount of light.

My next planned step is a weeklong blackout, but I've read that it can only be a temporary solution as well. Any advice would be greatly appreciated. I'm perfectly fine accepting responsibility for my circumstances, I just want it fixed!

Shidara

Well first stop using algea remover stuff and clarifiers, that can harm you fish.

Do a 50% water change then totally cover the tank for 4 ro 5 days, do not open to even feed the fish, they will be fine. After 4 or 5 days remove covering and do another 50% water change.

Should be clear.

__________________
SUCCESS IS MEASURED BY YEARS, NOT MONTHS!!!
220 Tank build
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That was the plan, but I wasn't sure about the moss ball - will the blackout hurt the moss ball? Should I move it to the betta tank during the blackout?

Shidara

It won't hurt it, and if you move it, you can transfer the green water with it to the other tank.

__________________
SUCCESS IS MEASURED BY YEARS, NOT MONTHS!!!
220 Tank build
http://www.aquariumforum.com/f15/sta...late-3253.html

Hi there,

You could always try and get yourself a filter with a UV sterilizer in it. I use that for my ponds which is extremely effective at destroying any algae..

Another thing I noticed from reading your posts is that your nitrites are not zero...Ideally this should not be the case if your tank is properly cycled.

How long have you had it up and running? Also cleaning out your filters too often will rid them of the beneficial bacteria, and if you do clean them make sure to use dechlorinated or old tank water as this will preserve most of the bacteria and you wont cause a mini cycle in your tank. I'm also a little surprised to see that your nitrates are 0ppm which is highly unlikely for a cycled tank.

Just my 2cents! Good luck!

__________________
195G Pleco - 13" Clown Knife - 14" Silver tinfoil barb - 7", 7 Clown loaches - 4-5" 1 Black ghost knife - 7" 2 Tilapias - 4" 2 GT's - 3"

Please let us know your results, as I'm having the same battle with my 10g tank. My 20 gallon is perfectly fine, but the 10g goes green after just a few days after a water change. It's majorly frustrating, and I hope your problem is solved, and I'll try the same on mine!

That was another option, although since the tank was fine at one point, I'd like to try to get back to permanently clean somehow. Does the UV sterilizer run constantly, or just temporarily or in short bursts? and will it affect the beneficial bacteria in the water?

The nitrites are pretty close to zero. I'm guesstimating that it's above zero based on the color chart in my test kit - it's pretty close to the "zero" color, but just a hair darker. Seeing as it was close to low, I thought it wasn't that big an influence. Can such a low - but still above zero - reading cause or maintain a persistent algae bloom?

The tank's been up for about three months, with one tetra moved from a 1.7 gallon tank at first and fish added gradually over the course of several weeks. Everything was beautiful up until I threw in that blasted algae wafer and zucchini, and now I'm regretting it every day.

One other solution I've heard of but hand't seen much info on was adding daphnia to the tank, to eat the algae and then get eaten themselves by the fish. Anybody have any experience with the little critters?

1.) UV Sterilizer - You could get one of these or something similar, you don't need a big one for your tank as they can get pretty pricey the larger the size.

BioCube Mini U.V. Sterilizer | UV Sterilizers | UV Sterilizers | Aquarium - ThatPetPlace.com

Basically the aquarium water flows through the filter which contains an ultra violet bulb that kills off micro-organisms in the water, the downside is that the bulb needs replacing once it wears out. But the pros outweigh that issue!

2.) Normally high nitrates cause algae blooms, you've probably already read up on the nitrogen cycle (Ammonia > Nitrite > Nitrate), so once your tank starts cycling which normally takes 6 to 8 weeks, ammonia is converted to nitrite and finally into nitrates, a good idea would be to introduce some fast growing plants temporarily like hornwort which is really fast growing and will outcompete the algae for nutrients that its currently using. You wouldn't need to add anything to help this plant so its a pretty viable option and wouldn't need any special attention on your part.

3.) Have you checked your tank for any dead fish? That could definitely cause serious water quality issues, make sure there aren't any.

4.) Keep your tank lights on to mimic the tropics no more than about 9 hrs a day, if you have them connected to a timer maybe you could try and reduce the time that they stay on while you combat the algae issue. Your post says you only have them on when you're around, have you got any live plants in there?

5.) As far as daphnia goes, you'd have to cultivate them yourself, here's a link to get you started but I personally would only go that route if the other options fail, http://web.cecs.pdx.edu/~davidr/disc...s/daphnia.html

6.) Try feeding them less for a couple of days as uneaten food will also mess with the water quality. Have you noticed any fish breathing rapidly and/or behaving strangely?

7.) My main concern is your water readings which seem to indicate that the tank has not yet fully cycled, if possible try and get your hands on filter media from a friend who has an established tank or get Seachem's stability
Seachem Products; Flourish Excel, Buffer, Kanamycin, Prime, ParaGuard, Purigen, Kanaplex which will aid in speeding up the cycle.

Hope you get the problem sorted, the death of your first pleco would have seemed to indicate stress, also water changes of more than 25% can cause ph changes especially if you have driftwood in the tank (this releases tannins which lowers the ph) and the new water has a higher ph, will definitely stress out the fish.

Good luck, hope the info helps even if it seems repetitve!

__________________
195G Pleco - 13" Clown Knife - 14" Silver tinfoil barb - 7", 7 Clown loaches - 4-5" 1 Black ghost knife - 7" 2 Tilapias - 4" 2 GT's - 3"

Is the UV sterilizer an "always-on" solution, or something you use as necessary?

Definitely no dead fish, and my nitrate levels are low to none. This is why I'm so confused as to the algae bloom - theoretically, I have conditions that wouldn't encourage it.

The only living non-fish in the tank is a moss ball. It looks good, but does't seem to be making a dent in the green water.

Noted. It seemed like a bit of work, and probably more than I'm ready for.

The only one I'd noticed that from was the doomed pleco. Everyone else is calm and normal - well, as calm as a yoyo loach can be!

Hmm, I thought those were good water readings. What should my target levels for pH, nitrate, nitrite, and ammonia be? I do have one piece of driftwood (wanted some height in my decor), but it was added after the algae bloom started.

Everything is helpful! Thanks!

Yes, I agree with the above posts.... It does not sound like your tank is fully cycled...or something has removed or killed off your beneficial bacteria. As mentioned above, a fully cycled tank will have no ammonia or nitrites in it and WILL have nitrates. It could have been one of the chemicals that upset the balance, changing the filter cartridge, even rinsing the cartridge in tap water... Also, are you using a liquid test kit or test strips? Another question... You said originally that the water is cloudy.... I just wanted to confirm; it's cloudy green, right? Not just cloudy? Cloudy milky water can be a bacterial bloom, not necessarily algae and may be a phase in your cycle. I don't have any experience with UV sterilizers so I can't add to that discussion, but if the water is green, as a first line of defense I'd recommend to save yourself the expense of a UV system and follow Susan's advice on the water change and blackout course. Then when that's done check your parameters and we can help you from there.

__________________
10 g planted community, 10 gallon danio/RCS tank, 10 g ghost shrimp grow out tank, 10 g blue pearl shrimp tank, 75 g in the works.

I'm using a liquid test kit - 5 drops of this, 8 drops of that. I had heard that test strips can be unreliable, so I splurged and got the more expensive kit.

As for the color of the cloudiness, it's definitely cloudy green. When I remove water from the tank, it looks like green kool-ade in the bucket, and decorations have a greenish tint when viewed from the side of the tank through a longer span of water.

My plan of attack is to go full blackout for 5 days.

If that still does't work, then it may be time for a UV sterilizer.

But here's something I haven't gotten a clear answer on: What is proper blackout procedure? What about feeding, vacuuming, etc? Should I do a filter rinse (in removed tank water, of course) during or after the blackout, assuming the water is clear? If the tank isn't clear after 5 days, do I go longer, or try something else?

Thanks again for the help!

Hey Shidara,

How goes the "algae war"? To answer your previous questions,
its entirely up to you whether or not you want to keep the UV sterilizer switched on all the time, but I suggest using it only till it eradicates all the algae, I HAVE to keep in on 24/7 on my ponds due to them being exposed to direct sunlight...

Like Cadiedid mentioned, your tank water readings should have no Ammonia, no nitrites, but it should have Nitrates, this shows that the benefitial bacteria is doing its job properly...

I'd say that this takes precedence over your algae problem as an uncycled tank is doomed to crash and kill your fish off, some might survive the ordeal but from experience most wont.

Blacking out your tank and fighting off the algae should be second priority in this case as once your tank cycles properly then at least your fish aren't stressed out with the Nitrites. I personally have never done a tank blackout before so I can't provide any advice as to how to go about it, but I'm pretty sure a google search will help you figure that out.

Good luck

__________________
195G Pleco - 13" Clown Knife - 14" Silver tinfoil barb - 7", 7 Clown loaches - 4-5" 1 Black ghost knife - 7" 2 Tilapias - 4" 2 GT's - 3"

So far, no real change. I removes the algone and covered the tank. We're on about 36 hours by now, and I haven't peeked yet.

This is where I'm getting confused. This tank has been running for four months. The water came from a 2G tank which had a pair of tetras in it for a month with no problems. After that, I added fish 2 per week until I got to 8, then waited a while for surface algae to build up before adding a cleanup crew of a pleco and amano shrimp. Shouldn't that have been ample time for the tank to cycle?

Could I have thrown the balance off somehow and forced a new cycle? If so, wouldn't ammonia and nitrites be elevated? Instead, I have 0 ammonia and trace nitrites at most.

This is what is confusing me - I've researched causes for green water, but every cause I've found doesn't seem to apply to my tank.

That's the thing - there are no nitrites! With no nitrites and no ammonia, how can my tank be cycling? From what I understand, Algae thrive on nitrates, and thus are probably devouring any nitrates in my tank, explaining the zero readings. That's the only way I can think that I could have zero- or almost-zero-readings for all three factors - a properly cycling tank with a massive algae problem.

I appreciate the advice, but I'm not sure I'm clearly stating my problem - everything I can see says I have a nice, balanced, cycled, well-cared-for tank, yet I have an unstoppable algae bloom. Unless I'm missing something about the cycling process, I'm really at a loss to explain the never-ending algae.

Tank looks cycled. Water from another tank does nothing in establishing a cycle in a tank. Anything else in that tank, providing the cycle was completed on it, may have helped though. If you are sure that ammonia and nitrite are zero, I would cover the tank for 4-5 days. No feeding, no nothing.

I didn't read the whole thread...does it get a lot of natural daylight? If it does it will not help. Best thing to use is a heavy blanket or comforter. Other things will have light penetrate. Once the 4-5 days is finished, do at least a 50% water change.

Okay, just finished a 5-day blackout, and things are . . . better, I think.

After the blackout, the water seems clearer, but definitely not crystal clear. I tested the water and it came up with slightly elevated ammonia and nitrites, as well as nitrates slightly high. I attribute this (hopefully) to dead & decaying algae.

I've changed 5 gallons, and will now wait and see. . .

In the short term, I 'd say the blackout didn't hurt my fish in the least. They are all accounted for and seem happy & healthy. The Moss Ball is also unaffected, still green and fluffy.

I plan to run it overnight and watch for increasing cloudiness. If I start to get green again, I'll go another 5-day blackout and see if it helps any more.

But all told, I might just invest in the UV sterilizer and be done with it . . .

Thanks for all the help!

If your filter uses a sponge, I would wash it out really good in some tank water or treated freshwater.

Good to hear you're making some progress!

It appears that your tank is going through mini-cycles, which may have been initially due to those algaecides...

If your fish seem fine, then you should be on the right track, first sign is heavy breathing and fish darting about the tank.

If I were you I would invest in a UV sterilizer just so you can be rid of the algae altogether, you don't have to run it forever, just till it clears the water totally, also like jrman83 mentioned, if your filter runs sponge, make sure its clean, I personally add some seachem to help the benefitial bacteria grow faster after every filter clean and water change.

Since I deal with ponds alot (I have 3 of them) I know how much of a nuisance algae can be, but I once read that some fish actually prefer the green water! (Not me though) Get a UV sterilizer that's suitable for your tank size (if you want to that is, they're not too pricey) and run it for a few days, if you have a friend with one, maybe you could borrow it for a trial run...

Either way, once again good luck!

__________________
195G Pleco - 13" Clown Knife - 14" Silver tinfoil barb - 7", 7 Clown loaches - 4-5" 1 Black ghost knife - 7" 2 Tilapias - 4" 2 GT's - 3"

Update number 2:

48 hours after unveiling, the tank is still slightly cloudy, but does not seem to be getting worse - if it is, it's at a much slower rate than before.

Testing reveals that my Ammonia is between 0 and .25 ppm and Nitrates are between 0 and 5 ppm. Nitrite appears to be holding at or just above 0 ppm.

Fish are all happy, healthy and hungry. Pleco is still cruising around keeping things spotless. For the moment, I think I'm gonna wait and see. If the cloudiness gets worse, I'm gonna do another blackout, and then if there's still trouble, the UV sterilizer will be given a good long look . . .

Thanks again for all the help!

Based on my current experience, I'd say try the blackout for 4 days. I fed them right before covering up, and the fish survived just fine. Afterward, change 50% water, and see what happens.

Good Luck!

Well, it's been a week wince the blackout, and the water never fully cleared up. The encouraging thing is that my green water either stayed the same the whole time after the blackout, or only got slightly worse.

I changed out 50% of the water and am conducting another 5-day blackout. After that, 50% water swap. If I still have trouble, it's sterilizer time . . .