Cleaning algae-encrusted gravel?


Okay, so I picked up a complete 10 gallon setup for free from someone who had gotten it about 4 months ago and no longer wanted to bother with it. Looking at the aquarium and fish, you can definitely tell.

When I got it home I did some water tests to see how bad it was and there was 0 ammonia, 0 nitrites, but the nitrates didn't even register on the test kit (goes to 160ppm). I diluted a cup of tank water in 3 cups treated tap water and tested nitrates again, got 80ppm . Needless to say, I changed 50% of the water and 15% every other day since and nitrates are back under control.

Anyway, the tank itself was in pretty poor condition, lots of black brush algae covering everything including the fake plant. I was able to scrub most of it off the plant and rock ornament with a toothbrush, but the gravel is totally covered in it. Each piece of gravel has about 1/8" of thick black algae on it.

My question is, how would I go about cleaning the gravel other than brushing off each individual piece? That black algae is tough and I'd rather not spend the whole summer cleaning. If it comes down to it I could always throw it away and get new gravel, but I hate to waste 10lbs of black gravel if it can be salvaged easily.


If it were me, and it was that bad, I'd toss the gravel.

platy ben

You could try a black out, I had green blanket algae once and it worked a treat. Just put a a dark blanket or something over the tank and leave the light off for about 4 days, if there are fish I nthe tank they will be okay without food for the time period. Leave the filter running while the light is out.


I'd just throw it away & get new gravel. Maybe a blackout would work but the dead algae will still be attached to the substrate & need removal. The rotting algae will play havoc with your water quality to.

I think I'd just get new gravel.


In my 55 gallon I just cleaned I filled 5 gallon buckets with the gravel and swished it around in water outside, drained the water, and then put the gravel in a strainer and the algae came off my rocks but I didnt have to much algae.

If not buy some new gravel.

Hope It Helps


I ended up emptying the tank completely and setting the gravel aside to dry. My wife reminded me I have half a bag of natural gravel (brown/tan) and some river stones left over from her betta tanks, so I just used that. I'll put up a picture or two of the new tank this weekend.

Thanks for all your advice!


Awesome I can't wait

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