If you want to take up much less space and still plug the capped lines, use slip bulkhead fittings and plugs. That will get that down to around 3.5” vs the bulky lines there now.
The intake strainers you have now look like the threaded type. You can order FIT low profile intake strainers from lifeguard aquatics. They take up much less space and won’t restrict flow nearly as much as those older style ones. You can trim out some material and it will flow even more. Be sure to check your fitting for slip or thread before ordering new ones if you want to use the existing plumbing.
Bulk reef supply has these for $3.50 ea. Search SKU: 209050
It will be found here, select your size. Looks like 1” to me.
https://www.bulkreefsupply.com/low-profile-bulkhead-overflow-strainers.html
There are 92k drops in a gallon. That slow leak isn’t the culprit but the leak needs be addressed nevertheless.
