Does the pump ever clog up with debris?

MUUUy bueno Paco!!

good job , i think you need change de plastic tube pieces for ceramic pieces or balls of ceramic ,filter better but your idea is simply and great and dont need spend too money fork give a good life for we little friends the fish :)

Good Job! Great Project! Especially if you are on a tight budget! Your fishies must love this! Make something else!!!!

I'm sorry, but using Gravel as a bacterial growth medium just won't work. Sure if you want to use an UG filter with Gravel as a growth medium then yeah, sure that will work, providing you have about 3 and a half inches of gravel or so on top of a good under-gravel plate like a Lee's or something similar. There just isn't enough surface area contained within the bendy straws and gravel.

The second issue I see here is the volume of water your filter has to pull through itself. A reliable filter has to be able to cycle all of the water in the tank between 8 and 10 times an hour.

This filter is a very novel idea, don't get me wrong, the idea is running in the right direction, but its not quite there yet.

If I can make one suggestion that would make this work so much better. Instead of using gravel in the filter, use Bio-max or something similar. An unfinished ceramic is no more expensive than aquarium gravel, and it is far more porous. The pores become a breeding ground for bacteria, and would increase the biological effectiveness of this filtration method by about 30% compared to gravel. The only problem here is that Bio-max has a tendency to go septic after about 6 months (All the dead bacteria clog the pores and suddenly its no more effective than the gravel you're using right here).

If you used a larger bottle, a 2L or something similar, you could utilize actual sponge as opposed to a filter pad (Again, more surface area, and easier to keep clean than cotton padding) then a layer of Bio-max or other untreated ceramic, a layer of Bio-balls or something similar (anything with a lot of surface area will do) followed by active carbon, peat moss granules, or other chemical filtration media (I like clearmax a lot) You could even run airline tubing from an airpump with a difuser into the top of the filter to increase aeration to keep temperatures down in cold-water tanks

I don't mean to come of as disparaging, just trying to spread the fishkeeping-love!

(P.S Your Tetra's look nice, consider adding some Blackwater extracts to your tank or Peat-moss to your filter to reaaaaaaally see their colours pop)

Can someone explain why the pieces of plastic straw are so much better for bacteria to grow in than the other surfaces that they would cause "your ammonia to shoot all the way down"? Don't the gravel and the filter mesh have more surface area?

DUDE, you have the same fish tank, filter and light set up as me!!!

OK so the only reason to really ever change a filter is for fresh "physical" filter? Do you ever have to replace the carbon and how often? and on the carbon note ... why not just put it in the foot of a pair of panty hose and throw it right in the top? (cutting the excess off of course)

could you use a gravel siphon metod, and not use a pump? (what I'm saying is could you suck on/activate a=the tubing and use it ?)

Thank you for this instructable video. This really simplifies it for me.

Great job! Can you explain why this wonderful system is not suitable for a primary filter? My 11 year old son wants to keep frogs from his science fair project and I told him "no" because of the cost, thinking primarily of the water filter (not to mention the delightful diet we'd have to keep on hand!). Thanks.

Awesome!... I just set up a small QT tank and dont want to spend 15 dollars or upward on a filter so..im elated that i found your video!.. I'm going to make one of these when i get back from the Christmas hubbub bub!...thanks!

A very good idea! And also very good for the tank and fish.

Fantastic. Great idea and choice of materials and execution. You have to make some more things!