green tank

[Azimiut]

I have had this 75 gal tank stocked with the same fish for more than a year since the last major overhaul(had to move tank for remodel). NEways, the tank has ALWAYS had a green tink to the color, never crystal clear.
I have a UGF with one powerhead to the UGF and one that is hidden on the bottom to move junk to the side filter, I know that the UGF is not the best setup, and a 75gal hang on filter running also.
fish:
2 oscars, 6"
2 dempsy 5"
Pacu (must go!!!) 14" to damn big
but the tank was green before that ******* grew up. what is with it? I do water changes, vacume gravel, everything. the quality is purfect. could it be the food? I have always used green ciclid pellets.
need canister filter, but $$. any ideas?

 

[wetmanNY]

Maybe the efficient biofilter colony in your filtration is breaking down phosphates from the fish food into inorganic PO4 that the algae can use:

solution: rinse out the filter media (in siphoned-out tank water) every four or five days til water clears.

Maybe the microscopic free-swimming zooplankton that graze on the green algae are suppressed (a medication regime?):

solution: a gallon of clear water from a fish-free plant nursery tank or a healthyplanted tank. A friend?

Maybe the phosphate taken up by floc in your gravel is freed when you do deep gravel-cleaning:

solution: siphon across the surface, but don't stir up the gravel.

Maybe the fishload is just pumping out more nutrient than your system can metabolize:

solution: that Pacu goes first. Then you have to decide: an Oscar tank Or a Dempsey tank.

 

[Kit Walker]

Well for starters you've got a pretty big bioload for a 75G (usually a 75G is the bare min for 2 oscars). I assume your HOB is an Aquaclear500? The problem is the amount of nutrients in your water with that bioload, is producing ideal conditions for algae. Plants are the best means to outcompete algae with nutrients, but with your cichlids unfortunately plants is not an option
A good size water change weekly to try and control nitrates etc, and possibly reducing the lighting if you can. Increasing filtration will benefit the tank, but you'll still have to get rid of those nitrates.

 

[Azimiut]

the dempsys' are small, 4-5 inches and have not grown beyond that in quite a while. M/F pair along with the oscars. is there a bacteria to add that might go for the free floating algae?

 

[Kit Walker]

I think perhaps your only solution is to try one of the extensive range of Seachem products. I think their product Prime actually neutralises nitrates and other unwanted by-products.
Eventually unless you are able to segregate the oscars and JDs, you'll end end up with 4 p**sed off fish in a 75G.