[MENTION=10185]chrono[/MENTION] -- Alright homie, I've got a good chunk of info for you. I'm keeping all my information based on my personal experiences fixing the issues you have now, that I had to fix myself. You've got a lot of solid advice here, so I'm going to throw out my 2 cents on some of the problems I think could easily be fixed, and give you a healthy, happy system.
Big believer in the Bulk Reef Supply: "52 weeks of reefing" series. If I can convince you of ANYTHING, it would be to watch that series, at the very least the ones that pertain to your problem itself. I've been keeping fish since I was 5 years old man, I didn't expect to learn anything from these videos -- I was wrong. Watching these videos has had the largest impact on my reefkeeping than any advice given by anybody -- Because it showed me not only products, but different methods, and a deeper understanding based on science.
Most of these videos are 10-12 minutes, one or two of them are much longer (SPS video is 37 minutes). They have so much good information in them, it's very worth the time.
My bad for making you watch your vegetables, but the information is actually stellar.
About Nitrates: Your nitrates are high. Now, having high nitrates within itself is
not a bad thing at all. But the fact that they keep creeping upwards of 50, while you actively combat it, tells me you haven't addressed the issue. Personally -- I believe the issue is your sand bed. At 3", you've got a lot of sand.. But the sand itself may not be the only issues. A list of things which could be responsible are.
- Food / Feeding habits
- Sand Bed / Not vacuuming sand (firm believer, I always vaccum my sand)
- Dirty RO/DI water
- Not enough sacrifices to the reefing gods (Anyone who says they don't feel this way once or twice is lying!)
A member here [MENTION=8656]M3ace9[/MENTION] has amazing looking SPS, and he keeps his no3 at 40+. Personally, I saw tremendous coloration improvement and overall coral health by getting my No3 stabilized at 25. Lately after my corals had recovered from the shock of my accidental ULNS (Ultra low nutrient system) I wanted to clean my tank up a bit more, so I had used Aquaforest Pro Bio S -- This absolutely wiped my no3 out completely down to 0, and did so very quickly..
If you wish your nitrates to be in a better area to suit your needs, I would say the first things to look into is slowly removing 1.5" of that sand, maybe 2".. Which sounds extreme. When you have 1-1.25" sand left, I would start vacuuming the sand when you do a water change from here on out. If you're trying to get a hand up on your nitrates, bacterias are absolutely effective, as is carbon dosing (Vodka, Vinegar) to help boost your bacterias.
Sand Bed: Your sand bed -- at 3", your sand bed is skirting the line between a "Deep Sand Bed" (DSB), which requires more work than regular sand beds, and is a nutrient sink without that kind of care. I think this will help with your nutrient issue, and having less sand means you can vacuum without having a huge bacterial bloom and nuking your tank (When I was in middle school, this is how I nuked my first reef. 4" Sand Bed, total obliteration from stirring the sand too much overnight).
My Cerith snails have slowly disappeared after adding my Melanurus as well. You need some snails to mix up the sand you do have.
Here is the BRS sand video
Properly Utilizing your Sump: You're correct, in that your sump is a little small.. But it can easily be modified without hassle to suit your needs. I'm talking getting a plastic cutting board, taking a saw to it, and siliconing that in a few spots to split a chamber or something like that. This is very simple, and pretty self explanatory, and 100x easier than cutting up glass. $10 will get you a caulk sized tube of silicone, and going to the 99 cent store will get you really cheap, thin cutting boards. A snip here or there and you can split up a large / pointless chamber, or divert flow to make it run to prefered chambers in the order that best makes sense.
Additionally, I would consider removing that section with sand and rubble and filling it with Seachem Matrix, or Siporax (bio-media). If you go this route I would heavily suggest putting it into DIY egg crate box, so it can be easily removed, or shaken around to loosen up detritus (my SPS freaking love this).
Here's the BRS 52 weeks video of Sumps
This sounds like a big pain in the arse.. It's a pretty light PITA, and utilizing your sump properly will give you much more control over your mini environment.
Refugium: The light you have is not helping your cheato. You're going to want something either in the warm spectrum (6500k) or a Red/Blue horticulture light. This will help your Cheato take off, for sure. It sounds like [MENTION=7067]Smite[/MENTION] is putting you on the right path, everything he said is rock solid -- I will also say when I was dosing nitrates, my p04 was always zero. Always. And I almost never had any Algae in my display, until I switched up to higher quality foods and Selcon. This sparked some algae growth, even though my p04 remained zero. Sometimes whats going on in our tanks is an oxymoron, or at least defies central thought. But I can tell you going 0 to 50 no3 made no difference on algae, conversely i'm right now at 0 no3/po4, and had an algae explosion after investing in higher quality food/selcon. Aggressive bacteria dosing and GFO are fighting it off pretty well.
BRS 52 weeks Refugium video
Alkalinity: Your alkalinity is a little low.. Honestly, I'm a HUGE fan of Kalkwasser. It helps regulate Alkalinity, Calcium, and pH stability. Nothing has made a bigger impact on my coral health than Kalk has.
The easiest way to implement Kalk is to mix 1-2 TSP per gallon into your ATO. It's also important to keep your ATO pump .5-1" off the bottom of the container. The reason is the Kalk slurry at the bottom will eat your pump. This will GREATLY help you out, it's dirt cheap, it's easy to maintain, and because you CANNOT run a reef without the foundation being stability.
BRS 52 weeks: Calcium, Alkalinity, and Magnesium
BRS 52 weeks: Kalkwasser
BRS 52 weeks: 2-Part dosing
SPS -- "Stability Promotes Success": That saying needs to be taken to heart. It's absolutely true, the goal is to have very little swing in every measurable parameter. You can run SPS in a handful of different environments, some people run ULNS, some run high nutrient, LED, T5, Halide, lower alk, higher alk -- THere's like 1000 ways to skin this cat.. The big thing here is that you absolutely NEED stability.
You WILL struggle if you 'don't dose anything'. You WILL struggle, if your Alk is too low for your Nutrient load. Example -- people who run ULNS run lower Alk, and higher nutrient run higher Alk -- Both work, but each style has an almost unspoken set of 'rules' to follow.
BRS 52 weeks: SPS corals
Yay! You finished reading my giant arse post! Celebrate by watching 52 weeks of reefing lol