Marine Pure in Sump--leading to high nitrates?

Susan Edwards · Mar 28, 2021

A year ago I added marine pure blocks to my sump. In addition to live rock in the refugium, some denitrate and prob. some mesh bags of rubble. My question is, could the marine pure be contributing to high nitrates? Getting clogged with junk?? The skimmer/sock section is always rather "gritty", maybe from the marine pure breaking down?

I also have boyds elite, purigen, prob. charcoal, phosguard, denitrate in that section. The last time I vaccumed the skimmer portion, and the return portion of skimmer was prob. Nov-jan sometime.

Anthony Scholfield · Mar 28, 2021

I highly doubt the marine pure is causing you high nitrates. It is supposed to house the beneficial micro things that help lower nitrates. I use it in all my setups to help lower nitrates.

The only thing i can think of when it comes to clogging is if you had a bunch stuffed in a small chamber before a filter sock where a lot of water couldn’t flow around it so it caught a lot of debris. Otherwise it shouldn’t “clog”.

I would look elsewhere for your high nitrates. Feeding schedule, maintenance schedule, water change amount and schedule to name a few possibilities.

What do you consider high nitrates?

Susan Edwards · Mar 28, 2021

The blocks are stacked against the front sump wall. Socks on back, then skimmer in middle. Other media around the blocks

High nitrates beg. october 160. After I removed sand and replaced, went to 80. (Over the 4 weeks it took me to do this, did more than a 100% water change. Since prob. Dec. started hitting 40. Recently have hit 15-20 range and now between 20-40 or closer to 20.

It's improved, but am trying for 10! I want to do a coral order so am focusing on getting tank "good". Last batch of corals in Oct or Nov (yeah, too early for the tank which reset). Softies all doing very well. Even have coraline plating. So maybe corals will do better now.

I do feed heavy. Bunch of piggy eaters. Feed 2x's a day. Was doing once a day for a long time but they seem happier with 2 x's. Water changes every 2-3 weeks. About 25-28 gal or so (125+25 in sump). Can't make up more saltwater than that at a time. Might need to get a 40 gal brute (have 32)