Citric acid question

[LOVEROCK]

Only had like less then a cup to 3ish gallon of water running a skimmer to clean , is the solution too weak ? I have no more citrus acid or would it take longer and if so how long the in advance

 

[andrewey]

I use ~100-150 grams/gallon. I know another common ratio is 1 cup/gallon. As yours is more dilute, I would just run it longer than you would normally would.