My tank water is green - help!

Question

My Tank   QUESTION: Hi,
I have a 46 gallon goldfish aquarium that I set up in October & cycled until mid-November and then added 2 fish and then waited a month and added two more. I went thru the brown algae phase and still have some on my walls occasionally, but in the last two weeks within two days of my weekly 80% water change it begins to cloud and then by day five, the water is green. It looks almost like the light bulb is green. It gets hardly any direct sunlight and the lights come on at 7AM and go off at 8PM. I have even been changing my filters every other week because they are dark brown & stinky.  I'm headed to the pet store tomorrow. Any suggestions?
Thank you!

ANSWER: Hi Kathy,

I have some really important information for for you regarding algae.

Algae will only grow when there are enough nutrients to support it.  Nutrients include things like fish waste, excess food, and unclean water.

Algae cannot survive without something to feed on, so when an aquarium is kept crystal clean, it gets no algae.

Lights play a small portion of algae's growth, as it can't spread without light, but the algae is there because of waste.

If you are using a canister filter, remember it must be cleaned every month, regardless of what the petstore told you.  If they are not cleaned, then the nutrificial bacteria inside it feeds back into the tank.  In otherwards...the poop filters back in, in smaller waste portions, forms nitrates, nitrites and ammonia.  These things FEED algae.  Yuck!

So, I don't know what kind of filtration you are using (I'm guessing canister - most people with algae issues either use canisters or Hang On Back filters that aren't rated high enough for their tanks).

You have a secondary issue in the tank.  You have goldfish.  Goldfish are really heavy wasters.  They poop a ton.  Their poor is prone to ammonia nutrifying bacteria and so we recommend that for each baby goldfish (1"), they get 5 gallons each.  It appears yours are larger, however, so four of them is okay for a 46 gallon aquarium, however I would nto add any other fish to that soup.  

Regardless of if you add fish or not, your filters may not be up to par.  Could you send me information as to the make/models you are using and how often you clean them out?  Cleaning means replacing the cartridges, etc.

If you set this tank up in October, there shouldn't have been much of a brown algae phase.  That lasts about a week, and it should have happened about 3 weeks into the tank.  If it lasted longer, it isn't a "cycle", as much as it is ammonia.

Another issue:  I can see your water.  It should not have a yellow tint.  That is ammonia and nitrites and that's what the algae is eating.

So, it all boils back to a couple key things.

1. Lights cannot be on more than 8 hours a day when you have these issues, til under control.
2. Clean the tank's water.  Do 25% water changes every 3 days for 2 weeks, until thewater in there is filtered out.
3. Do not add any chemicals!  The second you hit the pet store that is what will be recommended.  That will only cause more issues down the line, so I want to warn you before that happens.
4. Clean the filter thoroughly and change its media.  Do this every 2 weeks, because you have goldfish.
5. When you feed, only feed enough that they eat it off the top of the tank within 1 minute.  No excess should ever drift to the bottom.

I really hope this helps you out.  It's a good way to get hold of an algae issue.

To make sure water is being cleaned enough for the fish after about a week, take it out and put some in a white bowl.  The water should not have color.  It should be crystal clear.  If it has ANY color, this is negative.  Keep changing water...til it is clear.  From now forward, anytime you notice any coloration, it's bad news.

I'd be running some good filtration on the system.  Especially with four goldfish in it.  Goldfish are pond creatures.  But, we all love them and so we want them in the tank, not realizing how much they can exhude.  Yours are very pretty by the way ... my taste in goldfish!

I hope this helps, Kathy, and I look forward to hearing back about your filter.  I would love to help you find the right size for your system if that indeed is the issue.  I suspect it is at least, part of the situation.

:)

Happy fish-keeping!

Renee

---------- FOLLOW-UP ----------

QUESTION: Thank you so much Renee - you helped me out tremendously. I have an Aqueon filter that hangs on the back & is rated for 55 gallons.
I am headed to the store now and will do an 80% change today, including REMOVING my filter and cleaning it out and then 25% every other day to get on top of it. The food the store sold me is a SINKING pellet so it's very hard to rate how quickly they are eating it. I only feed about 20 pellets but I will buy the floating kind today.
Again, THANK YOU SO MUCH and I look forward to your thoughts on my filter. I've even considered getting a 2nd filter of a different type. Would that help?
Kathy

Answer
Hi Kathy,

Pellets are very dangerous to aquariums and water conditions.  Not only are they a waste of money, not providing your goldfish with sufficient nutrition, but even though many advertise that they do not cloud water, they are nothing but a nitrate factory (which causes ammonia).

These pellets may be another major cause of your water conditions.  It will cloud water and cause excess food to go uneaten.  Never, ever feed fish sinking pellets...even if a petstore employee offers them to you.  

Yes, I think the second filter will deffinitely help.  Though rated to 50 gallons, they often can't handle goldfish.

I hope this helps and keep in touch all you need to.  Please rate me. :)

:)

Renee