Add a skimmer to the left side behind the leather coral.

I'm running no skimmer and my only CUC is a pair of peppermint shrimp. I target feed my fish for the most part to keep uneaten food to a minimum. i let a few pellets go astray for the shrimp and that's it.

I've had nitrates as high as 100 ppm in my DT (100g), and phosphates around 1.0. Surprisingly my softies and a few LPS survived just fine, and some downright thrived. Last spring, I got my nitrates down to around 10 and phosphates as low as .28. This is with using bio pellets and MB7.

Unfortunately, I let things go a bit during the summer months, with fewer water changes, and let my bio pellets run low. By Oct, my nitrates were back up to 50 and my phosphates at .82. So I started changing my water more often (every 2 weeks vs 1 or 2 months), and started dosing with MB7 again.

In Nov, I filled my reactor with 1000 ml bio pellets, and within 3 weeks, my nitrates came down to zero, which is the lowest I have ever had. Then I changed my GFO, and now my phosphates are also down to zero, which is the first time I have seen that as well.

But would definitely rate a skimmer as essential.

when I ran skimmerless many moons ago it was on a 90g which was a lot of work for me. A smaller tank would be much easier as your water changes for nutrient export wouldn't be too much of a problem. Also helps if you're not importing a lot of nutrients obviously.

But in your case you were carbon dosing so it is essential to have one. But if the person was wasn't carbon dosing and was just doing w/c and GFO, they wouldn't require it.

I run carbon as well (not dosing though), but it is the bio pellets that require a skimmer. I dose MB7 to make the bio pellets more effective which is what brings down the nitrates. The MB7 also helps prevent cyano, mulm, clumping and other problems related to heavy bio pellet application.

Thanks everyone for the wonderful insights :) And sorry for the late reply; I was away from my laptop since morning.

Well I did a 50% water change today and the nitrate seems to have come down below 20ppm. Corals are a bit torn up right now. Almost everyone is closed (other than the freaking mushrooms!). Acros, oh well, are leaching mucus like they always do whenever disturbed. Fishes are doing well, as if nothing have changed. I don't know how but my cleaner and snails didn't get affected by the high nitrate. I just hope the corals open up soon. It has been like 4 hours and they still look beaten up.

Added a new pouch of chemi pure elite in the HOB. Also added natural denitrifier.

Was thinking of preparing another 5gallon water change for tomorrow. Should I do it or wait for a day or two?

The wc helped. Its around 10ppm. Will get Elos to find the correct reading.

Well your tank is big and have lots of space for the hermits to walk...mine doesn't have that :P Hemits had to walk over the zoas :P

Yap. Maybe that can also be a reason right?

You kinda did scare me of cucs LOL. Your "don't rely on CuC" still gets my eyes off any cuc :P

Come on I can never ever ever compare my tank with yours!

Yah I guess I have to cut down on the feeding. I just lost control in the last few days with the feeding!

BTW I went to concepts today to get Elos nitrate kit but it was closed. Will the store be open tomorrow?