Why did my Phosphate go up?

[DracoKat]

My tank's been up and running for nearly 7 months now, and for the first time, I am seeing Phosphate in my testing.. I am scraping algae off my glass more often.

I have not added anything new in the past month, no corals or fish.
Nothing died to rot inside the tank - no corals death either (The only 2 accidental fish deaths I've had, I've removed the body before it started to compose)

I've used Vibrant, my second dose was last week (The only different thing I've dosed)

Nothing changed with my lights, though I am going to have to order new T5 bulbs soon

Skimmer function hasn't changed, still cleaning it out every other day.

My chaetos are fading, but I think because the Par 38 bulb I used died, so I switched to standard 6500k CFL bulb

Other testings are showing normal readings.

Water change is tomorrow.

any ideas what is causing my Phosphate to go up?

 

[Diesel]

Main source of Po4 in the system is fish food.
Fish food that didn't got eating is the #1 Po4 problem ppl have.
Now if Po4 is up don't put off or wait till WC day, do it sooner as planned.
I think and that's just me vibrant is kind of killing or shutting down your macroalgae and for that you will see also a elevated Po4 # as in a maybe the same in No3.
Having a good nutrient transport as in a skimmer will work, remember there are skimmer and skimmers
Adjusting your skimmer is a ongoing thing if you dose a chemical like vibrant.
I tried it for three months and I get the same effect by dosing bacteria and carbons, as that's all what's in the bottle.
Just do your regular WC today and another one tomorrow, back off feeding the fish for the weekend and you should be fine again.

 

[DracoKat]

I actually don't feed the fish that much. once a day and sometimes I forget a day. oops.

I am thinking it may be the vibrant, wasn't sure since I am not seeing other reports.

thnak you for the prompt response, appreciate it!!

 

[Diesel]

I actually don't feed the fish that much. once a day and sometimes I forget a day. oops.

I am thinking it may be the vibrant, wasn't sure since I am not seeing other reports.

thnak you for the prompt response, appreciate it!!

Your very welcome