[Justin Kramp]

Hey all,

I have ALL the Green water anyone could want or rather not want...

Parameters/specs:
-40 gallon breeder
-finnex planted+ 24/7
-hamburg mattenfilter 1x1 ft roughly,
-active charcoal filtration inside
-black diamond blasting sand substrate with root tabs
-rocksss
-5 neon tetras, 1 guppy, and a bunch of dead shrimp that are now gone *cries*
-CO2 injection about 2-3 bps
-4 nerite snails

So, no algae on rocks, glass, or anything. Nada. Except water is so green you cant see through to the back of the glass. WHYYYY

had lighting at about 8 hours blasting for the first two months, no issues except green algae that stuck to everything so i toned down the light intensity, all good. went away with scraping and water changes...
a month later or so, roughly four months into this tank, green water explosion, tried to cut the light for about 2 weeks, ran out of CO2 anyways and figured I'd leave it off without the light anyways since i had it connected with the light to a timer. slowly the green water turned cloudy grey again, did water changes. cleared up ok, still a bit foggy. figured that whatever it is (diatoms?) died off and decided to turn light back on on the lowest intensity possible and add CO2 again, because plants were starting to really struggle. Did lots of water changes, pulled out dead plants and trimmed to promote growth on my sad carpet, but within days the green water is back almost as bad as before... i figured diatoms would go away by themselves? they clearly haven't yet, and i have zero algae on any rocks sand or plants. nothing, just green water. And yes, i have resorted to chemicals too, but gave up since its not working.

Anyone have any ideas?

 

[Maryland Guppy]

UV unit is the cure!

 

[Justin Kramp]

will that be a permanent fix? or if i turn it off will the green water come right back? will the uv unit kill good bacteria?

 

[Maryland Guppy]

If UV clears in 5 days run it for 10.

 

[Subconfish]

Do you have plants? If not a blackout would be great.

 

[jayo]

Have you tried doing nothing? It may go away on its own.

Do you have much water flow in the tank?

 

[babystarz]

will that be a permanent fix? or if i turn it off will the green water come right back? will the uv unit kill good bacteria?

The UV will kill the good bacteria in the water, but not the good bacteria in your filter (which has more anyway). From my reading, UV will not make a big enough dent in your good bacteria population to cause issues.