Loaches Online Forum

I have a HOB filter that is rated for a 5 gallon tank. My 5 gallon tank is filled with algae, and the filter tubing is brown. This tank has a filter for a tank 5-15 gallons. I need to switch them so that I can have a proper filter on my other tank. This means I need to scrub the filter clean of all algae, and be able to put it safely on another tank. How can I get all of the algae scrubbed out? I could do it with water alone, but I do not think that will work, because I have tried before. Could I use aquarium salt, and do it like I would clean plastic plants, or would I do something else?

Almost anything you do to kill or remove the algae will also kill the nitrifying bacteria.

I would keep all of the media, and just clean the actual plastic piece. I can put the old media into the new filter, and get new media for the larger tank.

In that case here are several ways to kill algae, and how to neutralize the chemical involved:
Almost all of these are a short soak, in a bucket, not in the tank, followed by the 'deactivating' treatment.

Hydrogen peroxide, straight from the bottle, or diluted to 50/50 with water.
Deactivate by thorough rinse. The last remnants of H2O2 after thorough rinse is not a problem for fish, plants, shrimp or other aquarium good guys.

Bleach, diluted 50/50 with water, or as little as 10% bleach + 90% water.
Do not leave it soaking too long. Few minutes if you use a stronger solution, half an hour if you use the milder.
Deactivate: Rinse well, then soak in water with a double dose of dechlorinator. If you can still smell bleach then rinse again, soak again.

Potassium permanganate: Make a rich pink solution and soak.
Deactivate with thorough rinsing, followed by rinsing with H2O2, then rinse again. Caution: this is dangerous material, follow all safety precautions about using it and disposing of it.

Very strong salt water. I would rub the dry salt on when the algae is still wet. The abrasion will remove the algae, and the bits of salt that dissolve will kill what is left.
Deactivate: Lots of rinsing. The remnant after lots of rinsing is aquarium safe.

Any of the materials used as aquarium fertilizers (KNO3, KH2PO4, K2SO4) rubbed on dry (same as salt).
Deactivate by rinsing. As above, these are aquarium safe at the low level that remains after rinsing.