tank clean up

Arron,
I think your first task (assuming you've been delegated to do the job) will be to totally empty the tank of water (however much is left) then remove the gravel and 'decorations'.

Really, this next step will totally depend upon the size of the tank and on how easily accessible it is - so for the moment let's assume it can be removed.

Take it outside and place it on a sheet of aeroboard, or similar and scrub it as clean as you're able to - but not with ANY sort of detergent. Salt is quite good to try - it really does depend upon how 'grubby' the tank has become. Those 'sponge-one-side-scourer-on-the-other' pads are very good, just as long as you don't trap any gravel in them (which might end up with scratched glass). And, of course, only use previously unused pads for fear of contamination.

There will possibly be a 'water-mark' which will be harder to remove, this can be attacked with something of an acidic nature - even vinegar can work with a good degree of good old 'elbow-grease'.

Once you have the glass to your satisfaction you can take the tank back to its home in the wall.

Now to the gravel - put some at a time into a bucket and run water over it, stirring the gravel from time to time. When the water runs clear, put that into the tank and start the next batch - continue until it is all clean and back in the tank. Clean your decorations also under running water then replace them as well.

Carefully re-fill the tank with treated water, pouring it into something like a jug set on the gravel, this should avoid it all getting spread all over the place. When you have it filled back up - assuming it's for tropicals - set the heater, filter etc back running - then starts the cycling, but there's enough information about that to be found in the Forum's 'pages'.

As hinted, if the tank is too big (or too impossible to move) to use this method you'll have to tell the Forum and no doubt someone will be able to help with alternative suggestions, but here's hoping it won't be.

John