Hazy Oranda Tank Advice

HI everyone,

Here are the tank parameters...

45gal Bow Front
Substrate (Medium and Small pebbles)
RO water... Using Kent RO Right to add minerals back into water

Fishless Cycle completed 1-25-2020
Added our 2 Oranda's ( maybe 4"-5" in length each, including tails)
pH stays very stable at 6.9-7.0
Ammonia & Nitrites have remained at 0ppm
Nitrates climb to about 20 - 40 ppm at which time I perform at least a 50% water change

Initially I had just a Seachem Tidal 75 HOB.
I have since added a Fluval 407 with a spray bar. (about 2 weeks ago)

The tank is always hazy, and once (maybe due to over feeding) the water got very dirty/hazy.
Water changes obviously fix this, but within 1 day or even overnight the water will be hazy again.
The Seachem Filter would always seem to be super dirty so I figured it wasn't able to keep up with the dirty little Oranda's.
I tried maintaining the Seachem weekly and then even twice a week to see if this helped.

I then added the Fluval in hopes this would add enough filtration to clean things up.

No such luck....
Still trying to fight the situation I changed out all the media in the Seachem to a layer of course sponge, a layer of medium sponge, and a layer of a fine sponge (filling the basket). In hopes that all the mechanical filtration would clean up the water.
The Fluval has the same in it along with the cycled ceramic rings to make sure my bacteria stay healthy.

I have tried purigen with no luck, as well as carbon.

The Seachem HOB is on the left side of my tank, and the fluval is on the right side (mounted on the back) the spray back is angled up slightly as to agitate the surface.

I feel like the filtration I have should be enough to keep the tank fairly clean, especially with weekly water changes, but it seems like they are not doing the job.
Is there something I missing, Should I have the Fluval setup differently? (Spraying down to agitate the substrate?)
Should I be using different media in the filters?
Is the substrate more of the issue? Holding to much waste and not allowing for good flow to the filters?

Hopefully this paints a good enough picture.

Thanks for any help you can pass my way!

 

How deep is the substrate and do you vacuum the gravel? Activated carbon has always worked for me. Not sure what else to suggest for such messy fish. It seems like enough filtration. Maybe just a lot of disolved solids? Is your tap water cloudy?Sometimes dissolved oxygen can make water cloudy.

 

The substrate is about 1" deep. We do gravel vac once a week along with the water change. I'm using RODI water so there should be no issue with that....

I changed the spray bar direction to straight down to try and stir up any detritus that may be getting stuck in the gravel.

I also ordered a UV sterilizer,. Figured it can't hurt to try it and see what happens.

 

The uv sterilizer should work well if it is some time of algae or other microorganism in the water. I'm really not sure what else it could be it sounds like you're doing everything right

 

How much are you feeding, and what type of food? A UV sterilizer definitely wouldn't hurt, and activated carbon in the filter will help for sure as well.

 

The main food they get is Repashy gel, occasionally some peas, shrimp, and very rarely some flake food.

We typically feed them a little in the morning and a little at night. We try to not drop food to the bottom or dump a bunch in. They like to be hand fed and will get several large mouthfuls of the Repashy at each feeding.

I had carbon in the fluval for about a week when I first added it and did not see a difference. I'll add some back in this weekend and try it again.

 

Your food and feeding schedule is good. Now you have the UV sterilizer (almost) and the carbon. Don't forget to keep up water changes, and update us as well.

 

I'll definitely update after I get the UV and run it for a few days. As well as the carbon.