Green Water - Can I Remove It Naturally?

[Juggler75]

Ok, so I donated a spare Aqua One 620 tank (20g) and stand to my cousin so she could rehome her goldfish (From this thread I am guessing they are fantails) from her 15l unfiltered 'starter' deathtrap that had been their home for 3 years.

She used to do 100% water changes whenever it got too green apparently. 4 weeks ago delivered the tank and stand and filled it up, filled half the filter with mature media and plonked the fish in. I visited a week later to find the thickest pea soup imaginable so next day I was back during the day (so I could judge light levels - no lights work in this tank so only naturally lit) and we emptied the tank of water and refilled with dechorinated water.

Week later at her sons birthday party, noticed the tank had green water again, so later that week visited again and did 80% water change, donated a large bit of bogwood that was heavilly planted with java moss, java fern and anubias (to try and soak up excess nutients) and we put bin liners as a backing and side covering on the side that faces a very small westerly window.

As I am visiting tomorrow for first day of school holidays, I asked about the tank to be told that it is very thick pea soup. Arghh.
I'm not going to be able to resist fiddling (already pulled out about 3 more pints of java moss from my tanks to donate) but then it hit me...

Ask you guys if there is anything more I could do. The fish themselves seem quite happy (as happy as they can be in a still too small tank I appreciate), the water stats last time I went were ammonia - 0, nitrite - 0 and nitrate 30ppm. I also gave 20 cherry shrimp on my last visit and apparently all are still there (gives idea of how dense moss is) so confident that there have been no spikes.

I have never suffered from green water ever before so unsure what more to try , apart from full blackout (which I can't enforce as its not my home), I have read much conflicting advice about using chems or leaving it to go naturally and just want to know if I'm going down right path.

Sorry for essay but thanks in advance for tips and advice

 

[Cazgar]

Green water won't affect the fish too much, regular water changes would help, but sounds like you've got a job on your hands to educate her how to look after her fish properly.
Good luck

 

[Juggler75]

I appreciate that apparently its not harmful to livestock but it is an eyesore and in an unlit tank makes it fairly hard to see them. I'm thinking educate the kids rather than the mum, although in the last few weeks she has bought a syphon, 2 buckets and some water dechorinator , that way the kids learn to keep their fish.

 

[Juggler75]

Well, pleasant suprise.

I got there yesterday and the pea soup was actually just tannins from the bogwood but not at all bad just a little dark. Removed the lid and a lot more light in the tank meant I could see everything quite clearly. Stuck more moss in there on some old ornaments I had, added some cambomba cuttings, a load of duckweed and some riccia (goldies having a salad bar) to try and make sure the back is broken on this and will visit later this week to make sure. I also got a couple of bulbs from lampspecs so shes currently running under instructions to keep lights on for only 4 hours an evening (but at least they can see the fish). Water was really clear when I left so hopefully I'll find it in the same way. Not my idea of a good looking tank but the kids love it

 

[Chtheo]

I am glad its sorted

until recently i have had rather green water in my main tank, the filter wasnt getting rid of it, and i would do a water change which would help (sort of) but soon it would be back to its usual colour, it wasnt pea-soup, so no where near as bad as some! but it was still a definate tinge. I had heard that a UV sterliser would help, i found one on Ebay for £20, tried it and within 24 hours my water was crystal! and still is!

Im pretty new to these sterlizers, so i dont know waht longer term effects might be, and the one i have goes inline witht he outlet of my fluval 405, there are various internl variants which i cant account for.

but if the problem should return, that may be an alternate route, or atleast something worth researching further?

 

[Juggler75]

Thanks, I was aware of using UV as a solution but couldn't really justify expense or figure out a way to integrate it into the in built filter on tank but very kind of you to give your solution to the problem.