Tideline 30in sump

Dc1338 · Mar 12, 2026

Hey, I have a tideline 30in sump with a single 7in filter. I currently have a 3D printed cup and I just fill it with polyfil. I’ve been looking at getting a roller mat, Has anyone installed one? I want to avoid modifying the sump, but I believe I will most likely need to cut it.
Thanks guys!

mcarroll · Mar 19, 2026

Dc1338 said:
I want to avoid modifying the sump, but I believe I will most likely need to cut it.

You're sure you need even more mechanical filtration? (Is this a regular reef tank?)

Dc1338 · Mar 19, 2026

mcarroll said:
Dc1338 said:

I want to avoid modifying the sump, but I believe I will most likely need to cut it.

Click to expand...

You're sure you need even more mechanical filtration? (Is this a regular reef tank?)

I need something that is more convenient than socks and filter cups, as it’s hard to access the cup.

mcarroll · Mar 19, 2026

Not always, but in many instances "less is more" when it comes to reef tanks and mechanical filtration.

For example, in a fish tank there are wastes that need to be filtered out. In a reef tank, everything that we were considering "waste" in a fish tank has a purpose, usually as coral food.

So if your system is reasonably in-balance in terms of the overall bio-load, consider going the other way and reducing or eliminating mechanical filtration.

If detritus is accumulating anywhere (this is often the perceived need for mechanical), spend these efforts and resources to improve flow instead of removing detritus. Detritus is coral food AND a mineral reserve for the tank (eg. alk and phos), so it doesn't fit the same role as "waste" like in a fish tank.

Funny factoid on detritus: When they lab tested what the best carbon source was for carbon dosing (to reduce NO3 buildup) in fish aquaculture systems....detritus from the fish system's filter turned out to be better than every artificial carbon source.

Dc1338 · Mar 19, 2026

mcarroll said:
Not always, but in many instances "less is more" when it comes to reef tanks and mechanical filtration.

For example, in a fish tank there are wastes that need to be filtered out. In a reef tank, everything that we were considering "waste" in a fish tank has a purpose, usually as coral food.

So if your system is reasonably in-balance in terms of the overall bio-load, consider going the other way and reducing or eliminating mechanical filtration.

If detritus is accumulating anywhere (this is often the perceived need for mechanical), spend these efforts and resources to improve flow instead of removing detritus. Detritus is coral food AND a mineral reserve for the tank (eg. alk and phos), so it doesn't fit the same role as "waste" like in a fish tank.

Funny factoid on detritus: When they lab tested what the best carbon source was for carbon dosing (to reduce NO3 buildup) in fish aquaculture systems....detritus from the fish system's filter turned out to be better than every artificial carbon source.

My main issue is lowering my phosphates that stay around .32

mcarroll · Mar 19, 2026

Dc1338 said:
My main issue is lowering my phosphates that stay around .32

How's your protein skimmer and the rest of your setup running?

Corals will eventually use up that phosphate, so if all else is well then try not to worry about it.

It's not the only possibility, but I'm wondering if phosphates are building up due to a lack of something else that organisms like corals need to grow like N in ammonia and nitrate? How are your NO3 levels?

If you're experiencing algae growth, you can't really control it by limiting nutrients. Manual removal is key. Often that means removal by hand as well as an improvement to the tank's cleanup crew (who remove it by nom nom). I.e. More herbivorous snails like Turbos.