So, You've Bought a Secondhand Fish Tank




Introduction: So, You've Bought a Secondhand Fish Tank

About: I'm a jack of all trades, master of none. But I can fix whats broken, and get my shit done.

With a little time off work ahead of me, I decided to upgrade my African Cichlid tank, as cheaply as possible. I've owned and built over twenty tropical and brackish (successful) aquarium setups over the years and decided my lone blue cobalt cichlid (George Michael) needed some more space and a few "friends".

I got him at just over 2cm about 6 years ago(everything wanted to eat him), now he is close to 6cm, so he had really outgrown the little 12 litre tank he's been living in (he ate everything he lived with)

Today, he is moving up in the world from a 12 litre glass box, to a 120 litre tank I picked up cheap.

It seemed a bargain price..

If something sounds too good to be true, it probably is.

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Step 1: So, We've Got the Tank...

Aaaaand its pretty awful.
Functional, definitely. Pretty? not even close.

The tank and bottom stand fit well enough and it looked sturdy... Mind you, it was cheap for a good reason.
Thats not mud on the bottom, and everywhere else, that there is pure chicken and duck crap. The car ride home with this in the back of the wagon was awesome.

About 1cm is looking rotted at the bottom on each leg too, apparently the ducks and chooks also pee on everything. Good to know, used to want some as pets...

Both sides and the back of the tank are painted with black oil based paint too, but I'm not going to think about that right now.. It's time to start on the stand and forget about that awful painted backdrop.

Step 2: The Stand:

Is an amazing book, by an up and coming writer called Stephen King, check him out....

This stand though, almost went in the bin.

was painted in 20 years worth of alternating black and white oil based paint..

The first pic was after I used a heatgun to scrape away most, then burned out 4 pads on the orbital sander.

Second pic was after 6 pads.

Third, and where I stopped was after 9.

Around here I started to wonder if 'Shabby chic' is actually a style chioce, or a "Eh? Probably good enough?" choice.

I went with the former reasoning, or, maybe thats just what I'm telling myself.

Step 3: Stain and Clear Coat

I sanded it all back as best as I could, but tried to be a little selective in the white bits on the legs and shelf.

Once all that was finished it got a wipe down with some vinegar, left to air for 20 minutes then hit with a pressure pack gloss clear can all over.

I removed 8cm from the bottom of each leg as they were a bit rank and rotted. I guess Fowl and Foul are similar words for good reason..


Starting to think this might work.....

Step 4: Time to Clean the Tank....

When this one arrived, someone had painted black oil paint onto both sides and the back..
Again, so many layers.

Only this time it was a bonus, it was so thick that it scraped off in sheets.

Once the paint was gone, I made the ol' trusty 1/10 white vinegar/ water mix (1 part vinegar to 10 parts water) and cleaned everything out.

Detergents in tanks is a big no no, vinegar and water will remove most calcified stains. If all else fails, a slice of lemon certainly will (tbh, you could definitely steal that alone and make an awesome instructable about it, tag me, I'll vote for you).

After that, and a wipe down with clean water and some paper towel (a couple of times) and she's good to go.

Step 5: The Setup:

Luckily (again) for me the old tank is about 15cm from the new tank, so I filled the new and cleaned tank with stones and 115 litres of clean water, connected the new filter and heater (step 7), along with a big handful of stones and 5 litres of water from the old tank into the new, then let it run for a few days empty.

I did this so the bacteria he was used to in the old tank had time to build up in the new filter media.

The substrate is from the old tank, its a 2mm mix of quartz & agate chips. Probably a bit too pricey to fill this tank with but will be a nice bottom layer full of good bacteria.

Step 6: Moving Time:

As I removed old water from the old tank, I also moved water from the new tank in to replace what I was taking, sort of combining the two and getting the fish used to his new home. This was a 3 day process.

On moving day, I just filled a sandwich bag with water from the old tank, scooped him up and into it with a net, sealed it with some air and dropped it to the new tank.

Ive heard pet stores say 15 minutes is fine to leave the bag in so your fish is used to the temperature, but I think thats probably a bit relaxed and left it in for a bit over an hour.

Step 7: Filtration and Heating

Okay, now I'm certainly no expert here but have kept a few tanks over 2ft before so going by what I know:

I had to work out the volume of the tank.
you can do this by multiplying the water level by wength and width of the tank in cm, the result is in ml.

e.g. tank is 10cmH, 10cmL & 10cmW
(10Lx10Lx10L=1,000Ml) it holds one litre.

When choosing a filter, I've found 5 full cycles an hour is minimum is needed

So, this tank is 120L, I need a filter that can pump a (minimum) of 720L per hour.

The same can be used to work out what size heater you need.

2cm of substrate is good, mine was a bit deeper in a few areas to help the plants.

There are also going to be a few extra fish and plants coming (including live feeders) so I went for a 1200L filter; I dont think you can over circulate your water.

Step 8: Rocks:

I added a few rounded river stones to give everyone a bit of cover and used some 100% silicone to make some rock stacks and plant holders. after leaving them to dry for 48 hours, I left them in a bucket of water for a couple of days. just in case.

Cichlids are territorial, so by being able to pickup and move little house structures and move them to another end of the tank and change things around pretty easily every now and again they will be less likely to fight each other.

Step 9: New Friends:

Once the rocks were happily in place it was time to add some plants and a few extra fish.

The plants I used are a 50/50 split of Aluminum plant (Pilea cadierel) and large Anubias (Anubias Barteri)

Substrate is 2mm river sand.

I went down to my local aquaruim and grabbed another two blue cobalts (one is orange, go figure) and a Malawi Eye Eater, male.

The guy down there also gave me a little unknown that was deformed (never grew a tailfin) said it might live, or it might get eaten.

We called it Maeby.

(theres pics, brown with vertical stripes, hit me up if you know what it is)

Theres also an albino peppermint catfish in there too.

With the new gravel in it will take a day or two settle and clear up.

Step 10: Finished

Time to sit back and enjoy.
a good aquarium is a million times better than television.

Im still waiting on a few kuhli loaches, but otherwise it's come up nicely.

Not going to lie, a big aquarium can seem like a big moneypit in the beginning, but, our family gathers around at feeding time to watch and we all stop to stand and see what theyre doing for a while when we're walking past.

And once you have everything you need the only real ongoing cost is food. water additives filters and the like can be expensive initially but tend to last forever.

Anyway, I hope this helped. will probably add to it as time goes on.

If youre a lake mawali cichlid genius type and I've done something bad please hit me up in the comments.

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    1 year ago

    after a very short google, Maeby might be a Calvus (also Cichlid type fish)? Mind you, I haven't the slightest of clues when it comes to fish but basically did what I always do when seeing an unfamiliar animal... google the description, then research further when finding something that seems to match the 'family' (maybe that's how I was found too, just not with google but books....) anyway, I do applaud your writing style which made me read a totally unnecessary ible for what I wanted to find!