Cycling.

How long should it take a 35-40 gallon tank to cycle?

The tank was running before, but when my aunt gave it to me we drained it, and when i got it home i rinsed it out with the hose, and cleaned the outside of the filter, and rinsed the gravel and plants off.

But i was thinking, does it really even need to be cycled?

I would say about 4 weeks to fully cycle that tank.
From personnal experiance you dont have to cycle it if your willing to do the extra work and only have a couple of fish in it. BUT for the fish's health i would advise against it unless its a complete emergency.
Cleaning the gravel and plants has proberly killed the bio system within the tank so i would have thaught that itll need comletly need re-cycling.
Useing a live bio formular will help a bit but i dont use that anymore since the last time i used it with fish in the tank it killed them all.

Well, i did not clean the inside of the filtr and the decorative rocks, are you sure just rinsing everything killed it all?

If you left the inside of the filter and the rocks, Their will still be some left but the chlorines etc in the water from the hose would have killed all the good bacteria in the tank that it touched. If your going to set it up useing those rocks and the filter(as long as they havent dried up) it should be quicker. If theyve dried up the bacteria would now be dead im afraid so it would be starting from scratch with that tank again.

ahhh i didn't think about the chlorines.

they didnt dry up, but boy am i excited about my new tank! i want to start with it nowww.

Im the same with all mine as well. Kid in toy shop comes to mind .

You could try a live bio in an empty tank for 7 days(i dont advise on API stress zyme+ though, it killed mine) then test the water and add 2 fish or something. See how things go. You may be lucky and get away with it. Stranger things have happened.

Failing that back to the good old goldfish if you have a pond.

My family knows nothing about cycling. They always just throw the fish in and never have a problem. So idk. I'll wait just incase though :/

My mothers always been like that with her tanks as well. Like to know how they get away with it. The only thing ive noticed is that shes always used undergravel filters.

Im going over to them in a couple of my tanks ill let you know if the theory works or not.

diferent filter serves different purposes..the undergravel filter generally use along with biological or ho filter in a big aquarium like 3 or 4 ft..the wastes from fishes or the extra food generally goes bottom of the tank and the undergravel filter absorbs it.this filter hasn't serve biological purpose or it is not like power filter.it just absorbs those wastages.so if u use the undergravel filter u need a biological or power or hod filter.

So i just got back from petsmart, where i had them test my water, and i made them test it three times, and every single time it said that all of the levels are perfect!

oh gr8.

You must have live plants or at least good cooties living in the under gravel filter. Under gravel filtering is my favorite, but it does need regular partial water changes. New aquariums are also something to get excited about,especially if you have MTS. I always wind up building a new DIY stand and doing DYI water parameter tests.

I hate undergravel filters. and all of you were wrong about me HAVING to cycle it, because since i set it up on sunday, the readings have been perfect, and have never changed the slightest.

undergravel filters are generally used along with biological or power filter.these undergravels are not use separately...an aquarium with biological and undergravel filter do the best way to clean it.where biological filter creates colony where as the undergravels take the wastage of fishes and extra food to make the tank perfectly clean..

Too complicated for me. I just have a 40 dollar filter that hangs over the side of the tank and I vacuum the gravel once a week.

thr filter u said is the hod or top filter i think,this is almost do as the external filter like eheim filter does and it do well.