Wondering about low nitrates and phosphate

[Danroo]

So I started my new tank for a 3ish months ago with dry rock. Now and I’m wondering about the behaviors of my tank, when my tank cycled and the ugly phase started had a diatoms bloom I was getting high nitrates like around 25ppm every week, tried to lower them through water changes which made it through 5 ppm and next week it will be back to 25 and high phosphate figured I wasn’t rinsing my mysis shrimp and just dumping it( worried cause water became cloudy and still is slightly ). This is also the time I changed change the filter media. Stated rinsing the mysis shrimp.

In all of this rock started having blue and green algae and some red one got mixed responses that it might Caroline or just cyno, I was just wondering what is making my phosphate and nitrate low is it the algae or rinsing of mysis?

oh I also have CUC as well.

 

[Jekyl]

Algae will soak up nutrients. I'm sure rinsing has some effect but I've never bothered to do so.

 

[Danroo]

I was wondering with the change of filter media. I’m using a aqueon HOB. Does not changing the filter cartridge also not filter out the nitrates and phosphates?

 

[Jekyl]

I was wondering with the change of filter media. I’m using a aqueon HOB. Does not changing the filter cartridge also not filter out the nitrates and phosphates?

You want to clean the sponge and change the floss a couple times a week.