Getting rid of green water with a diatom filter?

• pH:
• Temp:
• KH:
• GH:
• NH4:
• NO2:
• NO3:
• PO4:
• Iron:
• Dosing:10 mL iron chelate (1.0 ppm)

Notes:

Well, the tank is pretty much the same today as before in terms of the green water/ brown sludge. Increasing/lowering phosphates have not had much effect. There has been a decrease in other algae, but that might be from the increase in plant matter as the new plants settle in and the pruned Rotala starts growing back.

You can see the brown sludge sitting on the leaves of the Rotala indica in the picture to the left.

It seems that you cannot starve the green water to death without a significant increase in quick growing plant matter. My tank is pretty densely planted, but I've been switching out the fast growing stem plants with slower growing plants. So even though a tank may be fully planted, what's more important is how much of those plants are fast growing (nutrient sponges). If I let the tank become a Rotala jungle, I'm sure the green water would disappear, but I really don't want the plants to grow too much more than it already has. It already looks pretty wild and unkempt. The picture to the left is a side view of the tank at its most cloudiest. You can also see green dust? algae growing on the right wall, possibly due to my tinkering with the phosphates this week. The green dust algae seemed to crop up with the low phosphate levels.

My latest hypothesis is that the cloudy water (green water) might be related to the brown sludge that builds up on the plant leaves during the day. Maybe it's the build up of dead algae that settles out of water? In any case, after some research, it seems that my most preferred recourse is to filter out the green water algae via a diatom filter. I'm reluctant to get one because of the price (currently $90 at petsmart.com). Blacking out the tank would be a no cost solution, but I'm not thrilled about the idea of staring at a blanketed tank for a week. I could get a UV sterilizer, but it supposedly oxidizes iron and I already have enough trouble providing enough iron for the plants. Oh well, I'll probably get the filter, since I'm tired of the haze and watching pieces of brown sludge poo drift around in the tank.

A good link to info on green water.