The Fluval flex is an innovative nano aquarium with a lighting rig incomparable to other tanks.
Its very well designed with a nice curved front, plus filter compartments at the back to hide all the ugly parts.
The lighting is controlled by a remote control to allow you to find the colours that most enhance your fish and plants. I personally have one of these tanks (see below) on my office desk and its my favourite small tank thats reviewed on the site.
Fluval Flex small tanks review
The tank is nice and easy to setup as you’ll see below and the design of it with the curved front makes it easy to get a good look.
I’ve used this tank in my blog here – How to setup a planted nano aquarium – Which will walk you through all you need to know about the tank and creating a good look.
I’ve now got the tank fully up and running with a nice rock mountain looks as you’ll see further down the page.
The longer I’ve had this tank the more impressed I am with it.
It’s really easy to setup and maintain, which is key when choosing a small tank, but still gives you enough room to be creative with the scene inside.
I’ve got mine as a planted shrimp tank with some harlequins and rasboras in along with a few baby guppies from my larger tank (Where they won’t stop breeding!). You can buy the tank from Amazon above (Which is where I got it from – next day delivery).
Setting up the Fluval flex
I ordered my tank from Amazon and it was delivered the next day and well packaged. As you can see below the tank its well packed in its own box and was also covered in an Amazon box with air bags for extra protection.
Whats in the box?
In the box you get the tank, lights, remote control, filter pump and media, flow controller and a none slip mat to place the aquarium on.
Getting the tank setup
To start with you need to take the filer media out of the plastic bags and slot them in the holes they came from – still in the mesh bags, rinse them under some clean cold water, then return this to the middle column.
Then place the filer media back in the centre section. On the right site of the tank (the part with the hole and not the slots – some tanks vary which side its on) place the pump and out flow tube.
You then need to screw in the flow controller through the hole as you see below.
Now you need to rinse out the tank with clean water and wipe with a clean damp cloth – DO NOT USE SOAP!
If you’re setting the tank up as a tropical aquarium then you’ll need a heater to add to the tank – there’s loads of these available and our recommended nano heater is the Fluval 50 w heater.
You can get the exact one here that covers tanks up to 60 l so is still good if you have the larger version.
Here’s my initial tank setup with a rock feature, gravel path and the initial grass planting done.
It will be left like this for a few days before the filter is turned on, then the fish and shrimp added later.
After running the Flex like this for 3 days I then turned the filter and heater on and ran it empty for week to make sure the temperature was right and held. This also gave the tank some time to settle before adding any fish or shrimp.
The next step was to start adding some C02 to really help the plants grow – you can read about adding pressurised C02 here.
Adding the fish and shrimp
As we mention lots on this blog, it’s important to add the fish slowly and ignore the temptation to go to the local fish shop and buy everything you like the look of.
As this tank was setup as an over flow of my breeding shrimp and guppies I started with 2 red shrimp and 3 juvenile guppies (small but with a bit of colour starting on the tail).
I then left it another week and added more fish to complete the tank over the coming 3 weeks, just adding 3-5 at a time.
After it had been running for a few weeks and the grass was well rooted I’ve added a couple of small algae eaters – these can disturb the grass if its not well rooted.
I get asked a lot about fish going into the end filter compartment through the holes. In my tank I have left it uncovered as the fish and shrimp go in and out as they please.
In 6 months of running the tank I’ve only had one fish make it all the way to the filter pump section.
If this is something you’re worried about then you can add some thin gause over the cover to stop it happening.
The finished nano tank
Here’s the finished tank – (From our You tube channel)
Cleaning the tank
The tank will need general maintenance to keep it clean such as cleaning the filter sponges. These can be easily removed and cleaned under water.
There is a part of the cleaning that’s easy to miss – the filter in the pump!
If you don’t clean this you’ll notice the water in the pump section get lower and lower as the pump struggles to work.
Take the filter apart as shown below and clean the filter sponge to get it working correctly again.
Tip – You’ll need to remove the tube first to get it apart, this simply unscrews from the bottom.
I’ve been running the Fluval Flex for 4 months now and I’m really happy with it.
The water stays nice and clean and its relatively quiet to run.
Cleaning is a simple process, you just need to remember the small sponge in the filter pump or the filter will give up- as I found! (I’ll upload a how to clean video next time I do it)
If you’re going away here’s our guide for how to look after the tank – This does vary depending on what you have in it.
To run the lights on a timer you need to use an analogue plug rather than a digital one (This advice has come from Fluval directly).
A digital plug will reset to the mixed colour lighting, if you’re only away for a weekend or a few days then that won’t be an issue.
Here’s the kind of plug that you’ll need – 24 Hour Square Timer Switch.
I’d do a clean 3/4 days before you go and make sure the water level is nice and high.
Doing the clean a few days before means you can make sure they’re okay before you set of.
I’d set up a timer for the lights and turn off the C02 if you have a planted tank.
I’d reduct the lighting by a couple of hours a day to reduce any algae build up.
I’d us an appropriate feeding block for the fish you have.
As above with the feeding block and the plug.
Over 2 weeks its advisable, if you can, to get someone to check on the tank.
Some feeding blocks only last a week and the water level may beed topping up.
3 weeks +
Take the tank to a friends house and get them to look after it if you’re away for that long!