Properly Cleaning An Old Tank

[Florin Andrei]

I had a small tank for a few years. The fish (a few tetras) eventually died one by one of old age (were already mature when I bought them). Now there's only a few plants left, and the whole thing looks gross. I want to start over. I'll keep the hardware, but I'll start with new plants and eventually new fish too once the chemistry is right and the tank starts to metabolize ammonia on its own (I know how to do that part).
 
My question is - how to clean the tank? I'm a bit reluctant to use detergent on the inside, since traces of it may remain and contaminate the environment. Also a bit unclear how to clean the water pump - I'll do my best, but some parts inside are not reachable. Do I need to boil the gravel?

 

[NickAu]

 
I'm a bit reluctant to use detergent on the inside

Vinegar works well.
 

 
Also a bit unclear how to clean the water pump

When you say water pump can you please be a bit more specific? If you are unsure a photo of the pump  may help.
 

 
Do I need to boil the gravel

IMO, Unless you have pest snail problem or want to steralise it for what ever reason I would just wash it well in the tank water then put it in a bucket with some treated water for reuse, same thing for any filter media, and drift wood, It cant hurt to have all that good bacteria on the stuff when you reuse it.
I do not know if this method will work for longer storage times but a few days to a week shouldnt hurt the good stuff. Mayle even place a air stone in the bottom of the bucket.

 

[Ch4rlie]

First off, do NOT use any detergents or washing products, this will have a negative affect on your tank water when comes to setting it up again which in turn will surely affect your stocking when you do get more.
 
As NickAu says, vinegar works pretty well, or even a very diluted bleach solution something like 20:1 works as well. But both of these needs to be rinsed out really well.
 
Most filters, powerhead and pumps etc are usually able to take apart to get into the impellar housing and media storage areas etc, just a case of figuring out how to open them up, sometimes its clips/tangs that needs undoing or in some cases simply pulling the parts apart and even the odd screw to take out is not that unusual.
 
As for cleaning gravel, a good rinse in clean water will do the trick but doing this may remove some of the bacteria thats on the surfaces of the gravel, but there should still be some even after rinsing well as they are pretty resilient.
 
But since youre going to be cycling the tank again anyway, the bacteria on the gravel will help a little
 
In case you and others who are reading this, do not know of this article, this is a good method of getting your tank cycled as quickly as possible -
 
Cycling Your New Fresh Water Tank: Read This First!

 

[Florin Andrei]

Done. Vinegar worked well for the whole thing. I cleaned up with water first until it looked clean, then cleaned again with vinegar, then rinsed with water. Let it dry out, then put everything back together.
 
I was able to take apart the pump too, and cleaned up the inside pretty well.
 

 
I'll add gravel tomorrow, and I'll start the fishless cycle when the chemicals arrive in the mail - which should be in 2 days or so. I'll add plants when I have nitrates in the tank, and I'll add fish when ammonia and nitrites have stabilized at zero.
 
Thanks all!

 

[NickAu]

If you have not done already, Now is a good time to also start thinking of what fish you want and can keep. My suggestion is keep fish that can live in the water that comes out of your tap, With only dechlorinator added. Same thing for plants, I am a strong supporter of keeping it simple. Good hardy plants that require nothing fancy.

 

[Florin Andrei]

I'm thinking 5 tetras. Not sure about the plants.

 

[Ch4rlie]

Is your water sof or hard? And pH would be useful too.
 
This helps in determing what possible species would do best in your tank with your water stats.
 
Also, what is the size of that tank?

 

[Florin Andrei]

Average 66 mg/L - so it's soft to moderately hard.
 
pH is quite alkaline, but in the aquarium it has stabilized now at 7.8, after 4 days. On day 1 I've added the chloramine reducer, bumped ammonia to 2 ppm, and added a bacteria culture to start the fishless cycle. As of today, ammonia has decreased slightly, and I see traces of nitrites already; no nitrates yet.
 
pH was 8.3 on day 1 with the tank fully setup (heater, water pump, gravel) and all the chemicals described above. It's probably even more alkaline at the tap - the indicator turns super-alkaline when I empty the test tube in the sink. In the past, at equilibrium after a long time, this aquarium has tended to drift even lower, sometimes below 7. No idea why.
 
It's a 40 liter aquarium.