Are these intended for a sump?

[Unregistered User]

I can't figure out why I have these unless they were purchased for my sump. It's not a snug fit in 20 long, but fits nice. Is that what I'm looking at media for a sump? Yes, I admit I have only watched the Sump video twice, back in May & scanned a few diagrams. I'm not absent minded, lol, it was purchased for me for something.

Also, what sealant should I buy for sealing plexiglass in the sump?

 

[Peter K]

Reef safe silicone for the plexiglass in the sump.

Those both just look like sponges, you can put them in your sump if you want but not required. Provides an area for bacteria to grow if you ever need to add filtration to a QT tank on short notice. However, they also can get clogged pretty fast and become nutrient sinks in my experience if you are relying on the sponges to be your only type of mechanical filtration and aren't thoroughly rinsing them very frequently. Really up to personal opinion whether to use them or not, you can get much more effective bacterial filtration with marinepure blocks and filter socks / filter floss are much better than sponges for mechanical filtration in my experience. But then again reef keeping is all down to what works for you so you can always try them and if they aren't meeting your needs then you can try something new.

 

[Unregistered User]

Reef safe silicone for the plexiglass in the sump.

Those both just look like sponges, you can put them in your sump if you want but not required. Provides an area for bacteria to grow if you ever need to add filtration to a QT tank on short notice. However, they also can get clogged pretty fast and become nutrient sinks in my experience if you are relying on the sponges to be your only type of mechanical filtration and aren't thoroughly rinsing them very frequently. Really up to personal opinion whether to use them or not, you can get much more effective bacterial filtration with marinepure blocks and filter socks / filter floss are much better than sponges for mechanical filtration in my experience. But then again reef keeping is all down to what works for you so you can always try them and if they aren't meeting your needs then you can try something new.

Hippie me had to buy reefsaver... meaning I'm going to have a slow start. Should I put them in during the cycle stage pull them out down the road?

 

[Peter K]

I think it really depends on what your other types of filtration are. Both mechanical and biological. If you have plans for both of those that don't require the sponges you could always just cut them down a little and just leave them in the return stage of your sump so you'll have cycled media if you ever need it for an emergency qt or what not.