Reef Aquariums

Getting Your Tank Right From The Start

Most people treat a reef tank like it's going to run itself once they buy the gear and fill it up. That never works. I learned that after watching a client lose three months of cycle work because they had dosed calcium directly into an open sump during peak flow instead of the dosing drum method we'd set up. The reality is that Reef Aquariums demand a specific sequence of operations if you want anything stable to happen. Here's how I actually approach it when I'm setting one up from scratch.

The Parameters You Actually Need To Watch

I'll list the numbers most people think they need to track. Then I'll tell you which ones I barely look at anymore. Calcium: 380-450 ppm. If your SPS is pushing growth tips that are white or bleached, it's likely too low. My target is 420. Anything below 380 for more than two weeks will cause corals to close down and stop growing. Above 450 and you start getting calcium carbonate precipitating on your return lines, pumps, and heater guards. I've had to descale a bubble wand every six months after running at 460 for a while. Alkalinity: 8-12 dKH. This is the one I check weekly. If alkalinity drops fast—more than 1 dKH per week—it means your corals are building skeleton and your calcium or magnesium might be lagging behind. The corals won't tell you until they actually show stress on the tips.

Magnesium: 1250-1350 ppm. Don't touch this unless you're testing it. Most tap water sources and salt mixes get this right. The only time I've corrected magnesium was with a RO system that had gone bad on the remineralization stage. Once a year I test it and top off with evaporated water. That's it. Temperature: 75-78°F. Stable beats perfect. A swing of more than 2°F in a single day causes stress. I've lost zoanthids to a chiller that short-cycled because its probe was sitting next to a heater return line. Moved the probe away from the thermal plume and the problem stopped. Nitrates and Phosphates: Nitrates below 5 ppm and phosphates below 0.03 ppm. This is where people fight the wrong battle. Many keep phosphates at zero and wonder why their corals aren't growing. Some coral types need phosphates in the 0.03-0.08 range to thrive. The trick isn't hitting zero. The trick is finding the balance point where your corals grow but algae doesn't win.

How I Build A Reef Setup

Here's the order I follow. It's not fancy. It's just the sequence that avoids the most common failure points. First, I set up the plumbing. I use PVC for skimmers and return lines, silicone for custom sump baffles. Everything is valved so I can isolate sections without draining the tank. A 3-way valve on the return line lets me divert flow while working on the sump without stopping circulation. Second, the rockwork. Live rock isn't decorative. It's your biological workhorse. I use at least 1.5 pounds per gallon for a nano setup and about 1 pound per gallon for larger tanks. More rock means more surface area for bacteria and faster cycling. Less rock means you're relying entirely on your skimmer and a refugium to handle the biological load.

Third, the water. I mix saltwater in a separate stock tank, let it aerate for 24 hours, and then pump it into the display. The timing matters. If you add dry mix directly to the display, the local salinity spike can kill any bacteria on your live rock before they establish. Never do that. Fourth, the livestock sequence. I add bacteria starter cultures and a few hardy polyps first. Let them sit for three to four weeks. Then add snails and hermits. Wait another two weeks. That's when I introduce the more sensitive stuff. This order prevents ammonia spikes from decaying livestock and gives your biofilter time to handle each new input separately.

What Goes Wrong And How I Fix It

The most common issue I see is green hair algae (GHA) breaking out after a coral addition. It's not usually a nutrient issue. It's a light spike. When you add new corals, you often increase flow around them. That flow can shift the water column and change how light penetrates. The existing GHA spores pick up more light and bloom overnight. My workaround is simple: reduce flow by 30% for 48 hours after any coral placement, keep lighting at the previous setting, and manually remove any visible GHA with a turkey baster before it sheds. I also run carbon for 48 hours post-move to soak up any allelopathic compounds the corals release when stressed. Another problem I run into regularly is pH crash. People dose kalkwasser directly into the display during the day when photosynthesis is already pushing pH high. The dose hits a pH that's already elevated, the calcium precipitates before it can dissolve, and the corals get nothing. I dose kalkwasser at night, starting an hour before lights out. The pH is naturally lower then, and the solution dissolves properly.

Equipment I Actually Use Day To Day

I don't use every test kit on the market. Here's what I keep in my toolkit and why. Salifert test kits: Cheaper than Hanna checkers and accurate enough for weekly checks. The alkalinity and calcium tests are reliable. The phosphate test is less consistent and I cross-check it with a Hanna checker every few months. Hanna Checker for phosphate: The Salifert phosphate test fails at low concentrations. The Hanna gives me a reading I can trust when I'm trying to figure out whether my refugium is exporting enough phosphate or whether my skimmer is doing the work.

Tye's Test Kit for borate: Most people skip borate. I don't. Borate buffers alkalinity and keeps pH stable. When borate drops below 5 ppm, alkalinity swings get wider and harder to manage. Tye's kit is the only cheap way to measure it without sending samples out. Inline pH sensor: I monitor this in the sump, not the display. Sump pH is more stable and tells me what the corals are actually experiencing. Display pH fluctuates with lighting and flow patterns and gives misleading readings.

Common Mistakes That Cost Money

Overstocking is the biggest one. People add fish and inverts faster than their filtration can handle. I've seen tanks with 30 fish in a 75-gallon display where the nitrates sat at 20 ppm and the corals were all closed up. The fix wasn't adding more filter media. It was removing half the livestock and waiting six weeks. Under-skimming is the second one. People buy a skimmer that's rated for twice their tank volume and still complain about cloudy water. Skimmers work best when the water level in the chamber is right at the drip line. If the water sits three inches below the overflow weir, the skimmer is pulling air and not making foam. Adjust the water level, not the skimmer size. Skipping the refugium on a display-only tank. A refugium with chaetomorpha isn't mandatory. But it's the single most effective tool I've found for managing phosphates without chemical media. Chemical media like GFO works until it saturates, then it stops. Chaetomorpha grows continuously and you harvest it when it gets too thick. One harvest usually removes more phosphate than a full bag of GFO.

The Dosing Drum Approach

I recommend a dosing drum for calcium and alkalinity supplements. It's a small container with a peristaltic pump that adds solution slowly over 24 hours. The alternative is manual dosing with a syringe twice a day. Manual dosing works. But if you miss a dose or pour it in the wrong spot, you get a localized spike. The drum eliminates that variable. Here's what happens without a drum: I once added 10 ml of kalkwasser directly near a return line during a water change. The concentration at that point hit roughly 3x the normal level before mixing. A mushroom coral within six inches dissolved in 20 minutes. With a dosing drum running continuously, that spike never happens. Build the drum from a small bucket, a timer, and a 12V peristaltic pump. Cost is under $50. Save yourself the headache.

Lighting Is Not One Size Fits All

SPS corals need more PAR than LPS corals. A mushroom needs a fraction of what a torch coral needs. If you're running the same light intensity across the whole tank, the SPS in the back will be light-starved while the LPS in the front gets burned. I use LED bars with individual zones and dial them independently. Back zone gets 25% more intensity than the front. PAR meters are worth buying. I use a Apogee MQ-510. It costs about $200 and lasts for years. Without one, you're guessing. Guessing means you either under-light your corals or burn them trying to fix slow growth.

Water Changes That Actually Help

Most people do 10% weekly. That works for a lightly stocked tank. For a heavily stocked reef with large SPS, I do 20% biweekly. The bigger change pulls more dissolved organics out of the water column and replaces trace elements that dosing doesn't cover. The salt mix I use is mixed at 35 ppt. I check salinity with a refractometer after mixing and before adding to the tank. If it reads 34.5, I adjust with RO water. Adding salty water to a tank that's already at 35 ppt pushes the salinity to 35.5, which stresses corals over time.

Flow Patterns Matter More Than You Think

Dead spots kill corals faster than bad water chemistry. A polyp that isn't getting flow closes down within 48 hours and starts to rot. I use powerheads with random oscillation controllers so the flow pattern changes constantly. Fish don't settle into a predictable current, and neither should your corals. I position one powerhead on the left wall, one on the right wall, both angled slightly toward the center. The returns from the sump provide the third vector. That gives me three-directional flow with no major dead zones in a 90-gallon display.

When To Worry

Most coral behavior is normal. Polyps closed during the day means light is too strong. Polyps fully extended at night means they're feeding. If a coral stays closed both day and night for more than three days, that's the warning sign. Check the base of the coral for discoloration. If the tissue is sliding down the skeleton, it's melting. Remove it immediately. Melting tissue releases bacteria into the water column faster than anything else in a reef tank. Nitrates above 10 ppm consistently will encourage macroalgae growth on your rockwork. That's not always bad. A little turf algae on live rock is normal. The problem is when it covers the corals and blocks their light. Scrape the rockwork with a toothbrush monthly during water changes. Takes three minutes and prevents the big algae problems. Phosphates above 0.1 ppm is the threshold where I start investigating. Below that, most corals do fine. Above that, you'll see cyanobacteria patches on the sand bed and slow coral growth. The source is usually overdosing or undosing protein skimmer. Check both before buying more chemical media.