High Tech Bacterial bloom

I have a 50g cube with overflow to a sump, CO2 injection, RO water with Seachem equilibrium, and Micro/Macro ferts. (Fluval stratum substrate) 82deg Discus tank.

Filtration starts with filter floss followed by a micron filter mat, bio-balls, and Matrix (since removed). DC varios return pump.

Water would be crystal clear if not for the white bacterial haze.

Macro ferts are consumed within hours of dosing, and plants are showing signs of deficiency.

I installed a 36W UV sterilizer for 2 days, and this cleared the water completely. I took the sterilizer off, and within a day the water clouded back up.

I added some Seachem clarity (fluctuant) - and all it did was make the water look more cloudy.

I really don't want to run UV 24/7 as they say it does something to the plant nutrients, but it's beginning to look like my only option. Never had this problem before.

Nitrate, Phosphate will crash to 0 within 6hrs of dosing. I imagine if I stopped dosing, the cloud would go away, but the plants are already starving.

Why did you remove the matrix ? You may have removed a large amount of your BB

Are your bio submersed or emersed? They are much more affective emersed

Lots of questions here: Stocking? How old is the tank? Feeding schedule? Substrate? Sump volume? Turnover and flow rate? Any ammonia? Lighting? Sure there are more but start with more detail of the setup.

Understocked, 0 ammonia, and nitrite. 100x more filtration then needed. Could probably stop running water through the sump and still have no issue as the stratum is banked toward the back of the tank over 8" deep.

I dont see an option to upload a photo on here.

I pulled the Matrix to reduce anaerobic bacteria that was consuming Nitrates, and presumably Phosphates, but that still happens even without the Matrix. (I presume its the Heterotrophic bacteria bloom in the water column)

Ill probably just put the 36W sterilizer back in the mix, but plumbing it is a PITA.

Two Med Discus and 4 ottos. Discus keep laying eggs then eating the eggs.

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Another angle.

You're probably best letting it run its course as long as your fish don't show signs of stress (gasping, etc.). If the tank is new, you added fish recently or disturbed the substrate, that can cause a bacteria bloom.

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And here is the water a few hours later (having done nothing.) I fully suspect it will be cloudy in the a.m. again.

I don't know, maybe it is just a matter of time before it stays clear.

Anyone happen to know how much oxygen is in water of a given temp at equilibrium? -and/or- how much 3% Peroxide to a given volume it would take to double that level? I'm wondering if photosynthesizing plants are producing enough oxygen to kill off the bacteria that builds up.

The plants will use the O2 during the night.That's another reason why folks turn off C02 at that time.BB need oxygen to live.Injected CO2 at night,PH drops and can be an issue,too.

If your fish are not distressed I would just let it run its course. It will clear up. My tank was hazy for about a month after setup, then one day crystal clear....been gin clear ever since.

You don't really want to start throwing things at a minor problem like this. Be patient and let it run its course.