First off, I know some just from having been in the seahorse hobby since sometime in 2002. I wish I knew more than I do though as much of my knowledge is just from personal experience with the rest being from some research but probably more from information from Dan Underwood of seahorsesource.com who does an inordinate amount of researching. I find it hard now to learn things at my age as the mind is slowly deteriorating and memory is kaput.
I don't use filters in dwarf tanks but instead, use open ended air lines for circulation of water and surface gas exchange that comes with the turmoil at the surface.
I use a little rock for biological filtering, but do VERY frequent and large water changes for which frequency and size of changes affected by numbers of seahorses at any given time.
Dwarf seahorses appear to be quite lazy, preferring to stay hitched where they are comfortable and wait for the food to pass them by. Some are more adventurous than others and may do a bit of hunting but you can't depend on it so water motion has to keep the food continually distributed throughout the tank.
Moving the light source much further away from the tank will alleviate somewhat the congregation of nauplii close to the light source. I just use ambient lighting on dwarf tanks.
Unfortunately, social media has been the destroyer of good forums so seahorse.org has almost no traffic anymore. However, if you want to take the time to read posting that has occurred in the past you can sign up to the org and have to wait until someone authorizes your account, and then go to the dwarf forum which will just have the stickies shown as there are no current postings. Go to the bottom of the page and where it probably says 30 days in a box, click on it and change it to show all. Then the previous postings will appear.
Also, you could check out Tami's site to see if there is much about dwarfs on her pages.
https://fusedjaw.com/