Help: Brown Algae and High Nirates

[MNEEME]

I currently have a 10 gallon aquarium established and has been so for several months. One occupants are two goldfish from a fair almost 2 yrs ago.(Yes I know, I know.) I've recently noticed what I believe is brown algae growing on the gravel.

Filter: Dr. Fosters BioSystem25 (Up to 25gal)
Lighting: Marineland LED 18-24" (Recently decreased the time the tank recieves light:7hrs(was getting 12hrs) -- No direct sunlight)

API Test Results
pH: 7.6
High pH: 7.4
Ammonia: 0
Nirite: 0
Nirate: 40-160 (It so close I can't tell. It seems closer to 80)

Water changes usually occur every weekend. If not every other weekend. Roughly 30-40% changes.

Any ideas on what to do. Or what is causing the algae.

Thank you in advance

 

[fort384]

Are you gravel vac'ing the tank for your water changes?

How much are you feeding?

With the gold fish, if you aren't going to get them out of there (the tank is too small for them, hence the nitrate problem), you will need to do gravel vac and water changes at least once a week to get the nitrates down. The nitrates are a great source of food for your algae... if you get it down below 20ppm, it will help control the algae. Most likely, the lighting decrease is not going to have a huge effect on brown algae/diatoms. You actually probably want to go the other way with it to control it - increase the lighting rather than decrease. Decreasing is effective for getting rid of photosynthetic algae, but not diatoms.

 

[MNEEME]

I do gravel vac during every water change.

Twice day, morning and night. Only a small pinch.

Okay thank you very much for the advice.