I have a 150 SW
tank, it's been established for close to three years now and I haven't had too many problems with it. There are about 250 pounds of live rock in there right now -- I did a fishless cycle on the tank back in the day and the LR
was in there during that process.
I've been having some issues recently with nitrates being pretty darn high. I should say that I haven't seen anything but a nice, solid ZERO for ammonia and nitrites since I first put fish in this tank, but for the past month or so, the nitrates have been so high that my test kit hasn't given me a very reliable reading. I've already started doing MASSIVE water changes (120 gal
, where there is about 180 gal
total in the system) but mixing up that much saltwater takes a while so it's a time-consuming process.
I'm starting this thread because I want to brainstorm ideas for how to keep my nitrates down. I know water changes can GET them down, but I want to KEEP them down -- I don't want to be doing regular 120G water changes. I'm not positive on the science behind a lot of this stuff and what will actually work.
1. Put less nitrates in the system.
OK, so if I (feed less)/(have less fish)/(have less biological filtration) that will reduce the nitrates I put into my fish tank.
- I feed 5-6 days a week what my fish will eat in 2 minutes.
- Current stock is 5 medium damsels, 2 medium tangs, a DW Goby, 2 Bangai Cardinals, and some Nassarius Snails.
- I have 250 lbs. LR
and about 75 lbs. of live sand.
...I do not want to reduce the fish in my tank. Sure, feeding less is an easy thing to do, but will it matter if I don't reduce the LR
in the tank?
I don't want to just start taking things out of my tank to reduce nitrates unless I know exactly what I'm doing; I thought the bacteria that live in the LR
would just process whatever fish waste was created into nitrates, and the population of bacteria would adjust to how much fish waste was created, but is there more to it than that? What is the right plan of attack here?
Once my nitrates are down to a level where I can get some precise measurements (may be a couple of weeks before I'm able to execute that many WCs), I'd like to figure out exactly how many ppm
-of-nitrates-per-day my current setup produces and maybe see what kind effects tweaking certain things will have...
2. Take nitrates out of the system.
Water Changes. Yeah. I know. Some routine maintenance is required -- or is it? I've heard that the most successful SW
tanks don't require water changes for the purpose of keeping nitrates down, since other methods of nitrate export are able to regulate the nitrates in the system so well that they can stay below 5ppm without water changes.
Other methods of nitrate export:
Protein Skimmer - Well, I have one, and it certainly removes -- stuff -- from my tank, but is that nitrates? The skimmer I have is certainly "too small" for my tank, but it's the biggest I can fit in the little space I have for it, so improving this isn't *really* and option for me.
Algae Turf Scrubber - So this is a thing that some people have built... is there something available that isn't DIY? How effective is this?
Macroalgae - So this is where a good portion of my failure comes in. I've tried my very best to have some macroalgae in my refugium, but never have I gotten anything to show any growth, and if I understand correctly, if it's not growing, it's not removing nitrates from your system. Right now I have a ball of chaeto down there that I'm not sure is even alive at this point. I've tried asking around at LFS
all over the place, and in the past year, they say they haven't been able to get their hands on the stuff. I can order it online, but I'll pay like $50 for a couple of golf ball-sized chunks that are half dead when they get here. I've heard anything other than chaeto could be dangerous for a tank. If there's something about an effective macroalgae setup that makes it work, I guess I'm missing it. If this is a really effective way of nitrate export, maybe we should debug my setup?
Smart people: thoughts?