help please not sure whats going on

my tank has been running now for 5 months all has been good. last week i started getting red slime i treated it with redslime remover and did a 40 gal water change in my 90 gal with refugium. i did a water test this morning and i have ammonia at .025 and my nitrite at .025 not sure how this happend but i need help i have fish and some coral in it.

 

coral is doing good still open. clownfish are good also but powder brown tang has been hidding under rocks all morning

 

Red Slime Remover is meant to kill bacteria, since cyano is a since bacteria. Your biofiltration is also bacteria. I suspect you've killed at least part of your biofiltration.

I'd run some carbon to be sure you get the RSR out of the water, and dump a good live bacteria preparation into the tank.

You may need to add a buffered ammonia binder such as Ultimate or AmQuel+ in the interim, but use it sparingly, as even the buffered preparations can crash your pH if overdosed.

Look to the causes of the cyano (usually excessive PO4 or NO3, or poor localized flow) as opposed to putting a band-aid on the problem.

 

What water do you use? RO/DI, conditioned tap, distilled?

 

i use ro water

 

Sounds like you de-cycled the tank.

 

This can also be caused from old bulbs. What type and how old are your bulbs??
T5's can last anywhere from 6 - 12 months before experiencing a shift in spectrum which will begin to cause your red algae.
What's your Nitrate, you didn't list that either.

You might wanna invest in a phosphate test kit to see what your nutirents are.
40 gal water changes are no fun...

 

Good call on the old tubes FB...

 

Not near a window or real sunlight?

 

+1 on po4 and lighting. Test po4 and no3. I use phosban in my 180 reef with great result. Water changes will help nitrates.