How to lower nitrates and phosphates with Matrix?

Leon Gorani · Oct 28, 2020

I have noticed that my fish have been acting weird lately, and I tested my nitrate and phosphate, my nitrates were at 35 ppm, phosphate was at 1.76. Yes I know that is pretty high but I have not been overfeeding my fish, and I only have 3 fish in my 30 gallon tank. I have a ton of coral and they are all doing just fine. My 2 clownfish have not been swimming up at the top as usual and they look like they are breathing heavily but they aren't sitting on their side or anything. I don't know what to do because I keep up with my water changes and I thought everything was doing just fine. I had my court jester goby die yesterday out of no where, he was doing find the whole day then just died out of no where. I also have a yellow wrasse and he is doing fine, swimming everywhere.

I have a hang on the back CPR Aquatics refugium on my tank, it has a lot of old established matrix, and Marine Pure bio filter blocks in there. So I thought that would help take care of the nitrates. I do have a protein skimmer running too, but I unplug it overnight because it is too loud (tank is in my bedroom) So I need help with what I can do to hopefully lower nitrates and phosphates. Do I need to take out the old Matrix and replace it with new Matrix after a few months? Any tips on media I can use to lower phosphates or nitrates?

Also my clowns fins looked much more pointed than they do compared to just yesterday, I have long fin clowns and my larger ones fins look more pointed than usual. you might be able to see that from the second and fourth picture. My clownfish have also not been eating anything for the past two days, they usually eat just fine, but they stopped and I'm not sure what's going on with my tank. I have ordered a new Red Sea tank and I was hoping to have that set up and hopefully I would have better luck with my nitrates and phosphates with the new tank, since it is larger and I will be using better filtration methods with the new tank. But I am waiting for it to be delivered, might take another month or so.

here are a few pics of my fish and the tank.
Thanks.

Dragon52 · Oct 28, 2020

#reeefsquad

Randy Holmes-Farley · Oct 29, 2020

There are many ways to reduce nitrate and phosphate and any or all of them can be used. Growing macroalgae or turf algae, organic carbon dosing, various phosphate binders, various types of denitrators, skimming more, etc.

I discuss them in these articles:

Phosphate In The Reef Aquarium
https://www.reef2reef.com/blog/?p=3184

Nitrate in the Reef Aquarium - REEFEDITION

LeftyReefer · Oct 29, 2020

Matrix is good, but I believe that it requires low flow conditions for it to do much lowing of nitrates.
I'd keep all the old matrix and just add some additional matrix if possible.... and then reduce the flow through the matrix to maximize it's ability to process nitrates.

rmurken · Oct 29, 2020

I don’t think Matrix is a really going to significantly lower NO3 unless you set up a low-flow situation as @LeftyReefer suggests. Not aware of any effect on PO4. Consider what @Randy Holmes-Farley suggests for nutrient management.

As to adding/replacing Matrix. I wouldn’t add more; I wouldn’t get rid of what you have. Doesn’t need to be replaced. You could rinse it in water change water, but it’s hard to imagine that’s necessary if you have a filter sock or floss before it in your filtration system.