New used aquarium



Needed some quick help. I just came across this site a few days ago as I was researching aquariums.

Yesterday I got a good deal on a freshwater 90 gal tank and so I brought it home. I was wondering if I need to do anything critical before I mess things up.

When I went to pick the tank up, it was full of water with a few fish in it. I believe he had it setup with african cichlid's and a few other fish but had sold most of the fish already.
So I got the tank with a stand, and canopy. It came with a T5 light fixture with a blue light bulb and a white light bulb.
He gave me the rocks that were in the tank (about 100 lbs) and 2 Magnum 350 filters (one with with a carbon container filter and the other with a particle filter)with tubing.
So we emptied the tank down to less then about 1/2 inch of water and he removed and kept the fish he had.
There is sand on the bottom of the tank with a bunch of small snails (100's).

I have read most of the beginner faq's and about the nitrogen cycle.

So is there anything I need to do immediately? or should I just start over with the cycle? His tank seemed pretty healthy.

Should I keep the sand with the snails in it or get rid of the snails? Should I keep it sand or change to gravel?

I think those are my most urgent questions as I continue to read all the faqs and past posts.

Thanks for your knowledge!


Welcome to Fishlore!
If the filter cartridge didn't get dry than its still cycled and it doesn't matter if you keep the sand or snails in.


If you trust the source, then by all means keep the filter media and such, Just make sure to use water condition before running water into the filter as that would kill the bacteria needed for the cycle.

Sand or gravel is personal preference. I think sand looks nicer and is easier to keep clean. Also easier on certain bottom dwelling fish, and easier to plant live plants into should you choose to do so later on. I'm assuming the snails in the sand are mts. These are good (imo) to keep in sand as they stir the top inch or so. But they do breed quite easy.

And welcome to fishlore !
  • Thread Starter


Thanks for the replies. I'll probably do what you guys said and keep the filter media and hopefully the bacteria survive the transition.

I looked up the snails and they are MTS. There are so many of them though. But I guess they will be good to keep the algae counts down.

Once I get the tank filled, conditioned and then circulating again, I assume I'll just follow the tests until they show no ammonia and nitrites? Then proceed with the fish.



With no fish being in it, you will need an ammonia source to test. Look up fish less cycle for tips . Although your cycle time should be short if not very short because of the kept media.

Once you are cycled add fish slowly in order to give BB time to adjust to the increasing bio-load.


In years past I bought maybe two or three used tanks. I actually don't remember if all of them were what I'd call a live tank but I do remember one that was up and operating. Maybe it's just me but even today if I bought a used tank I'd do what I did back then and that was start fresh. Granted none were 90 gallons but I dumped everything, cleaned out the tanks, washed new gravel, and restarted the whole process. I'm kind of in the mode that if there are issues with a tank they're my issues and not something I inherited. Just me....


Personally, I agree with Randyk47. UNLESS the source you got the fish from is a trusted one, and the media didn't dry out already. I've acquired tanks from previous owners that seemed to know what they were doing in the hobby until I looked closer at the equipment they used with the tank. Long story but, it became very apparent that the previous owner didn't really know what he was doing, or he didn't care to run things properly. I would proceed with caution if you do not personally know the previous owner. Seeded material in media and substrate can be GREAT, if all is good and healthy.

One more thing, assuming that the new aquarium is glass, triple check to make sure that your aquarium is level. If it's not level there could be some twisting that could cause a break once it is heavy with water.
  • Thread Starter


Got the tank filled, conditioned, and circulating. its been a few days already. Waiting for my test kit to come in the mail. should get it today or tomorrow.

Since there are a few hundred MTS in the tank already, will they help produce the necessary ammonia to help with cycling the tank or do I need to add additional ammonia source?

I decided to keep the filter that I got with the used tank, hoping that helps to cycle the tank quicker.

So another question is that since it came with 2 magnum 350 filters, one is filled with charcoal and the other has a water polishing filter. Which one contains the "media" that the bacteria grow on? I am assuming it is the water polishing filter.

Most photos, videos and links are disabled if you are not logged in.

Log in or register to view

Top Bottom