Sumps are wonderful---but--if they're piling higher and deeper with brown fluff, you have your answer as to why you can't get your nitrates down.
To clean a sump there are several ways. First, make up some new salt water. Shut down your system. pump your sump dry and discard the mucky water into a bucket. Use that to swish off all rubble, etc, before replacing in the sump. Wipe the sump dry to get all the corners. Refill with new salt water to the system-shutdown level, and turn the pump on. Instant sump clean AND water change.
Second method if you have a sump with so many partitions nothing can reach them, is to disconnect it, bucket your return pump (because it leaks) and take it to the back yard with a strong garden nozzle to blast the crevices out.
Third method, in event nothing else works, but not with a sump that has become absolutely awful because the awfulness would be dangerous, is to put on a filter sock and put a small pump to continually agitate the area where most brown gunk collects (a flashlight will tell you) and just run the system, changing filter socks daily until you are clear.
You may want to consider a better skimmer if you are having nitratre trouble that nothing resolves. The crud has got to go, and if your skimmer isn't getting rid of it efficiently, you're going to pay the bill in lost specimens and heartache. Check around. The cone-type skimmers, which froth, seem to pretty good; if yours only relies on bubbles, it may not serve a tank well enough, particularly when you move up tp a 50 gallon tank or thereabouts.
There's a lot of argument pro and con to be had here, but I've just been there with my own tank (nasty lot of dieoff of inverts and sump from a power out) so I thought I would pass my hard lesson on.
To clean a sump there are several ways. First, make up some new salt water. Shut down your system. pump your sump dry and discard the mucky water into a bucket. Use that to swish off all rubble, etc, before replacing in the sump. Wipe the sump dry to get all the corners. Refill with new salt water to the system-shutdown level, and turn the pump on. Instant sump clean AND water change.
Second method if you have a sump with so many partitions nothing can reach them, is to disconnect it, bucket your return pump (because it leaks) and take it to the back yard with a strong garden nozzle to blast the crevices out.
Third method, in event nothing else works, but not with a sump that has become absolutely awful because the awfulness would be dangerous, is to put on a filter sock and put a small pump to continually agitate the area where most brown gunk collects (a flashlight will tell you) and just run the system, changing filter socks daily until you are clear.
You may want to consider a better skimmer if you are having nitratre trouble that nothing resolves. The crud has got to go, and if your skimmer isn't getting rid of it efficiently, you're going to pay the bill in lost specimens and heartache. Check around. The cone-type skimmers, which froth, seem to pretty good; if yours only relies on bubbles, it may not serve a tank well enough, particularly when you move up tp a 50 gallon tank or thereabouts.
There's a lot of argument pro and con to be had here, but I've just been there with my own tank (nasty lot of dieoff of inverts and sump from a power out) so I thought I would pass my hard lesson on.
