Water keeps going green

[The_Hawk]

Hi everybody, nice looking little community you have going on here :)

Long time noob, first time poster...

My 4 year old son got a small fish tank for Christmas with a single fish in it, very small, nothing but a 'gravel filter', by which I mean it drew the water from under the gravel through a tiny pump. The tank would always go green very quickly so I thought since we hadn't managed to kill a fish in 7 months we could move up to a bigger tank with a couple more fish.

So I head out and buy a new 34L tank and a couple more Goldfish to go with the one he already has.

This is the brand we got.
http://i20.photobucket.com/albums/b202/Th3_H4wk/Other/fish/IMG_0144.jpg

Built in light, filter and pump in the lid.

Anyway, the guy in the shop says change 25% of the water fortnightly and 50% monthly, got the dechlorinator stuff and some saly stuff which is being added to directions. PH tends to move up from 7.0 to about 7.2 or so but that comes down easy enough...
I not 100% but I'm sure he said change the filter monthly, but rinse out with each water change.

Problem is it goes green in under a week and I have no clue why. Tonight I changed out 16L out of 34L and it now looks like this to give you an idea of just how green the water was getting.

http://i20.photobucket.com/albums/b202/Th3_H4wk/Other/fish/IMG_0141.jpg

Now I did a 100% water change the first time round since it was sooo green which the shop tells me wasn't the right thing to do so I did about 50% a week ago, then 50% again this week and you can see the results.

Any ideas what I'm doing wrong? Should the filter be changed more often, especially in a new tank?

[wombat1100]

Hello and good to see you posting questions with pics :-)
generally i find that excess lighting is the cause of green water, how long do you run the llight for per day? is the tank in direct sunlight from windows?

[yarra2]

Hi, and welcome. Maybe it's not only the lighting but the water needs to set up its own bio-process over a period of time. Also goldfish are particularly messy. What I'm getting at is to not change the filter but just rinse it out in the old tank water.

[The_Hawk]

I picked up some new filters today since I needed them anyway and was talking to the guy in the shop. Seems that it's algea in the water and since it's not sticking to the tank walls it's most likely because of too much light plus maybe overfeeding.

There is something he can give me to help keep it under control, but the best option is to reduce the light to the tank. Since it's out of stock at the moment I will have to do a bunch of partial water changes over the next few weeks till it comes in (or find it elsewhere).

Seems to be a case of try a few things and see what happens.

[wombat1100]

Hi, and welcome. Maybe it's not only the lighting but the water needs to set up its own bio-process over a period of time. Also goldfish are particularly messy. What I'm getting at is to not change the filter but just rinse it out in the old tank water.


I have never had a tank go green like that just from set up, from what i understand algae needs to be fed light and waste to grow, so it shouldn't be a part of the bio process
I could be wrong but thats my take on it.
I think what you have is suspended algae and you can get a UV filter for that ,I would be doing partial water changes and have NO light on it until the problem clears up. and if its near a window I would move it before spending money on chemicals or alternative filtration

[yarra2]

Yeah, I agree. I was looking at it from another angle - thinking that with a high Ph like that from the start it might have been the water from the start.... add a bit of goldfish crap to that and the algae has started to bloom so quickly.

Anyway TH, let's know how it goes and we'll do what we can to help.

Mike

[The_Hawk]

Seems the wife was leaving the light on for about 12 hours a day, since then it hasn't been on at all, although the nearby window is open most of the day providing natural light and the problem isn't nearly as bad.

So I have done a 50% water change and replaced the filter, will do that again in the coming week and we might just be onto some clear water here...

The plan for this tank would be natural light during the day + a few hours of the built in light at night (it's used as a night light when my boy goes to bed and so he can watch the fish). If this means we have to cut down on the natural light, so be it.

[yarra2]

Could be you're on the right track then... I'm thinking that when it all settles down there are different types of lighting that you could consider. I had a small aquarium once that had inbuilt LED lighting and that never caused a problem with the water.

Cheers,

Mike

[joz]

Natural light is tricky to control so careful relying on it.
I don't understand why the local aqurium would suggest changing filters??
Or was it the type of filter you changed?

Under gravel filters work fine as long as you have enough gravel covering them,if the gravel layer is too thin it won't work.

But the main reasons you tank will go green is excess light combined with excess nutrients in the water.Cut back on light and the amount fed to your fish...my suggestion.

:)

[The_Hawk]

Natural light is tricky to control so careful relying on it.
I don't understand why the local aqurium would suggest changing filters??
Or was it the type of filter you changed?

Under gravel filters work fine as long as you have enough gravel covering them,if the gravel layer is too thin it won't work.

But the main reasons you tank will go green is excess light combined with excess nutrients in the water.Cut back on light and the amount fed to your fish...my suggestion.

:)

The filter was filthy (and just about up for replacement anyway) so that was my call, as for excess light and food, yep looks like we had both of those. Cutting back on both seems to be getting there (although I think we are still a water change or two away from a really clear tank).

How often should I (or could I) change the water if I'm going from a green mess aiming for clear?

[joz]

Just to clarify,if your using an under gravel filter there should be no need to replace it.
usually just a gravel clean over the top of it should suffice.

Water changes will clear the tank temporarily but the only way to get clear water is to stop it going green intially.But no harm in extra water changes, your fish will appreciate it.

[The_Hawk]

It's not a gravel filter (the tiny old tank was). The tank we are using now has plastic cage with a fibre top filled with carbon as a replaceable filter, under that is a rough sponge like thng, then under that is some short ceramic "canelloni" shaped bits.

Only the carbon filter bit has been replaced.