How Often Should I Remove Fish And Throughly Clean The Tank ?

Having just posted in your other thread I can now maybe see the problem...

Firstly in answer to your question regarding how often to do a thorough clean.. never!.  I do a thorough clean of a quarter of the tank each week and a general clean on the rest while I'm there. This way I don't have to risk removing items and deep cleaning then which can remove beneficial bacterial from the tank (similar to those in your filter) on these surfaces.  Also I just read:

Planting substrates are mainly designed to trap and slowly release nutrients to plant roots, and often come pre-loaded with food — that means ammonia. The moment you start trying to rake through them, you release those nutrients into the water column, and that in turn will lead to an outbreak of algae. http://www.practicalfishkeeping.co.uk/features/articles/2016/10/13/how-clean-is-your-bottom

Now to combine the threads and answer your question on algae... I would reduce your fertiliser dose simply because a lot of your plants are relatively slow growing, and your substrate is a source of nutrients and/or possibly releasing some into the water already making it easy to overdose in such a small volume of water.  This should help limit algae growth.

Hi
I do use a syphon and push it into the gravel , it's the type you suggested sue from pets at home with the hand pump in the tube . It does get lots of gunk out and I do this weekly when I change the water . But it's impossibe to get it all ? I just want to rinse all the stones, I think the filter at the back needs changing as it had a lot of black stuff come out when I rinsed it ( in the old tank water ) earlier this week. 
I'm not going to fertilise so often and turn lights off a bit . I'm a bit parinoid about fish disease as lots of betta owners have fin rot !
Allison

I have the same 64litre tank. The filter is not the best design but interpet (manufacturer of P@H Love Fish branded products, though they are very much a cheaper alternative) also offer an 87 litre aquarium which uses the same filter so it can (in their view) treat higher fish loading than would be possible in the 64 litre.  That said the P@H one does not come with the biomedia cartridge like the true interpret does.  I have added bio balls in a mesh bag (https://www.amazon.co.uk/gp/product/B007VCHNMS/ref=oh_aui_search_detailpage?ie=UTF8&psc=1) to both replace but also improve upon the volume of available biological media in the original interpret filter (https://www.amazon.co.uk/Interpet-Internal-Cartridge-Filter-CF2/dp/B00ITQKZIE?th=1).  This fits nicely behind the carbon pad.  I very rarely replace the algaway pad which removes phosphates. This will be useful when you first set up the tank to limit algae growth and by the time the chemical wears out it will become a further biological treatment stage - just squeeze in dirty tank water to refresh it and replace.  Fish getting behind it hasn't been a problem for me, but jumping in has so I'd definitely recommend covering it in some way.  I'd also recommend a black background and heater cover as it nicely hides the equipment in the tank.

Hope that helps !

 

As sue suggests - don't change the media - their just trying to sell the stuff - the algaway pad is currently the only thing holding your biological media - just rinse/squeeze it in tank water removed during a water change.  The problem also with these types of filters is that there is no way to trap the gunk on the surface of the filter pad as you remove it from the filter and it tends to end up back in the tank - removing the filter unit as a whole is the only thing I've found to work, but I also wonder if a measuring jug or similar under the filter outlet would work when removing the filter pads...