my goldfish tank's water is crystal clear and the filter is working fine but goldfish creates a lot of waste so their manure collects on the bottom of the tank(which is bare), is it okay or will it create ammonia spikes? I know that you can siphon out the poop but then you will be doing that every other day, is there any alternatives to this?
btw my tank is a 40 gal with 2 goldfish and 2 pangasius(and 2 red neon lobsters), I'm planning to add more...
Frequent water changes are necessary, no matter what you do. You could get an under-gravel filter and some gravel, which will hide the poop, but not get rid of the ammonia, nitrites, and nitrates. The water will eventually become toxic.
Take a look at https://www.thesprucepets.com/water-changes-1381886 for more information.
Short version, change out 15-20% of your tank's water weekly with dechlorinated (https://www.aqueon.com/products/specialty-equipment/siphon-vacuum-gravel-cleaners) water. A great way to do this is using a gravel siphon (https://www.aqueon.com/products/specialty-equipment/siphon-vacuum-gravel-cleaners). That will help you get the water and the poop out at the same time.
