YOu have probably a penguin Biowheel for a filter. I have used them with good success. the wheels hold the beneficial bacteria. the actual filter is a cartridge that slides in vertically from the top. Most filters can be easily disassembled and cleaned. water only. no soap! where the tube bends and goes into the filter is a piece that pulls out and covers the impeller. pull the impeller out carefully and clean that up too.
The cover will have a cut out for where the water falls back into the tank.
as far as water first or gravel, it is not that critical. if you put the gravel in, just put a saucer down to deflect the water as you pour it in. if you put the water in first, dont fill the tank more than half. if you are thinking about putting live plants in, look around at the substrates that are better for plants. One thought, I use sand and try to get my tanks looking like nature. I got sick of blue gravel and plastic decorations rather quickly.
I got my ammonia from the dollar store as it had no surfuctants as the "better" ammonias in the grocery store all did. surfuctant means soap and soap means fish that cant breathe. fill that tank up, and get that cycle started.
do you have friends with tanks that are up and running? get a handfull of gravel or a used filter cartridge and put it into the tank. the penguin might have a basket in the filter itself that is great for holding a scoop of gravel. it will jumpstart your cycle. you have to remember to feed the tank ammonia, and you may look crazy feeding invisible fish for a few weeks, but you will have a happier tank in the long run.
good luck
The cover will have a cut out for where the water falls back into the tank.
as far as water first or gravel, it is not that critical. if you put the gravel in, just put a saucer down to deflect the water as you pour it in. if you put the water in first, dont fill the tank more than half. if you are thinking about putting live plants in, look around at the substrates that are better for plants. One thought, I use sand and try to get my tanks looking like nature. I got sick of blue gravel and plastic decorations rather quickly.
I got my ammonia from the dollar store as it had no surfuctants as the "better" ammonias in the grocery store all did. surfuctant means soap and soap means fish that cant breathe. fill that tank up, and get that cycle started.
do you have friends with tanks that are up and running? get a handfull of gravel or a used filter cartridge and put it into the tank. the penguin might have a basket in the filter itself that is great for holding a scoop of gravel. it will jumpstart your cycle. you have to remember to feed the tank ammonia, and you may look crazy feeding invisible fish for a few weeks, but you will have a happier tank in the long run.
good luck