91g Reef

91g Reef
91g Reef

After many years of absence I decided to start back up again with a modest 91 gallon aquarium. Here in Calgary finding a good LFS is hard as there are only a few scattered across the city. Fortunately when I walked into Wai's Aquariums I found a place I felt had good customer service and good selection of both dry goods and livestock. But boy was I shocked at the cost of everything. A yellow tang is $600, A small frag of Acropora is $50.

Tank

I picked a Red Sea Reefer 350 G2+ which is a 91 gal (342ℓ) total system volume tank. The main display holds 273ℓ of water and the sump 69ℓ. Funnily enough the system is advertised as 90 gallon yet on the warranty serial number sticker it is listed as 91 gallon. Since I already had two 90 gallon tanks I chose to pick the 91 gallon value for uniqueness.

The tank measures 120cm x 50cm x 53cm (L x W x H). Or for the confused Canadians - 48" x 20" x 21", or a 4ft tank. With the stand the system is 140cm high (55"). The front and bottom glass panels are ultra clear (low iron?) glass 12mm thick, and the two side panels are 15mm thick.

This model came with the ReefATO+ auto top-up system - but more on that later. When the tank was delivered, the cabinet had to be assembled - it was flat packed like Ikea furniture. The cabinet material is MDF, not plywood like some reviews mention. There are multiple adjustable feet to level the tank. I decided to place it on a rubber sheet that I got from Home Depot as this tank stands on top of a wooden floor in my living room on the first floor of the house. Without the rubber mat the feet would have had left dimples. That said, only once I tear down this tank will I know if that is not the case 😟...

The sump is nice and large, however I do have a couple of gripes with it. It fits almost too perfectly in the cabinet. It is almost impossible to remove the door from the hinge. It is nearly impossible to hook up any magnets or clip on clamps to the sides of the glass panels. There is only 1cm of clearance between the glass and the cabinet. I could not connect the Red Sea ReefATO clip for the RO water tube to the side wall as the clip needed 5mm more space. I would not have minded if the sump was smaller by 1cm both sides.

Mechanical Filtration

Previously I would have used the natural settling of the sediment in the sump as mechanical filtration, but I discovered a new and better way - a reef mat. I acquired a Red Sea ReefMat 500. The basic idea behind it is quite ingenious - the system lets the water from the overflow flow through a chamber where it is forced to go through a piece of filter paper that is on a roller, and once clogged up with sediment and other unwanted material, the sensor detects the rising water level and advances the roll to expose new filter paper. This lowers the water level and the process repeats. This way there is almost no maintenance - unlike sock filters that have to be cleaned regularly. Since this is new technology we will see how well it works. Update 2024-09-07 The reef mat works fantastic.

I have a Red Sea Reefer DC Skimmer 600 - actually I purchased the AC version but it had a terrible humming noise echoing into my basement, and it over skimmed terribly for 3 days. So I got the DC upgrade kit and converted it - and could not be happier. The motor is a bit louder but the frequency of the noise is such that it is only audible in the room the tank resides in, I cannot hear it at all in my basement so that is a win. Also, with the DC pump I could dial it back and it does not over skim any longer. It is currently set to 80% pump power.

Chemical Filtration

Underneath the ReefMat is a small holder for GAC (Granular Activated Carbon). I placed the small bag of GAC that was provided with the unit in the holder so that is currently my only chemical filtration. In the future I will consider adding a small Phosban 150 reactor with RowaPhos.

Biological Filtration

For biological filtration I have 40 lb. of dry rock (coloured pink and supposedly full of freeze dried bacteria - sounds a bit far fetched to me). Seems like live rock is something that one cannot really get any longer. I refer to the type full of life. I also bought 20 lb. of proper live rock from an old sump from an LFS - the rock is pretty barren but hopefully full of bacteria. I got another 7 lb. rock from Benjamin's Aquarium from their display tank - it came with some green star polyps and four mushrooms. I did not want those but what can you do? Perhaps they survive... Update 2024-09-07 They did survive!

I moved one rock to the refugium.

The sand bed is shallow - about 40 lb. of aragonite and 40 lb. of aragonite Fiji pink sand, and 5 lb. of aragonite live sand. The first two bags were properly washed before I added it to the tank. The live sand sachet was empty so I guess no bacteria...

Heating/Cooling

One 300W Eheim jager heater in the sump is responsible for maintaining a stable 25.0°C. It is currently set with an allowable range of 24.9°C - 25.2°C, reason being if I set it to 25.5°C the heater stays on during 00:00 - 08:00, when the house cools down to 18°C. Hopefully this saves some money and still be acceptable.

I have nothing for cooling - that is a worry for the summer. Update 2024-09-07 It seems like the house air-con is enough to keep levels stable.

Additives/Topup

The tank came with the Red Sea ReefATO+ that manages water level in the pump compartment, temperature and the pump in the RO reservoir - currently a 30ℓ glass tank in the other compartment below the tank.

I have a Red Sea ReefDose 4 unit to dose Alk, Ca and Kalkwasser. As of 7 Sep 2024 I am dosing 5ml of Ca, 12ml of Alk and 500ml of kalkwasser daily. I have a small Jebao MLW-5 wavemaker in the sump underneath the dosing outlets to ensure rapid mixing with the water.

Return Pump

The return pump is a Red Sea ReefRun DC 5500 pump, capable of moving 530 - 1450 gph, with a maximum head height of 3.5m and consuming 10 - 40W. It is really quiet, and has a nice controller for speed control. I initially had a Jebao DCP-5000 return pump - worked well, but I wanted to have RedSea's app control over the pump.

Flow

Two Red Sea ReefWave 45 gyre pumps are mounted on each side of the tank. A third Red Sea ReefWave 25 is mounted vertically on the left rear wall of the tank, to help fill in the gaps behind the rocks. They are all set to varying schedules, roughly 50% power. Initially I had a Jebao MLW-30 and MLW-20 in the main display tank, but I removed both in favour of the gyres.

Lights

Two Ecotech Marine Radion XR15 Blue and one XR30 Pro supplies the lighting for the tank. Photoperiod is 08:00 - 16:00 with a 1 hour ramp up and ramp down phase. Colour spectrum is 100% on all bands except green and red that are at 20%. Total output is 30%.

In the refugium I have a Neptune GRO 20W LED which connects to the Neptune power bar - neat, one fewer power adapter.

Automation

The Neptune Apex Pro looks after the power bar, temperature, pH, ORP, tank water leak as well as RO tank water level. The Red Sea equipment have their own software and automations, and so too do the lights and wave pumps. I am using the LLS-15 liquid level sensor in my sump (final compartment where the return pump is located) and the RO tank. I have found that this sensor, especially in my RO tank, is completely unreliable. It would measure well, then below 12cm or so it would start measuring higher and then flatline. I have therefore built an ultrasonic depth sensor that is way more accurate and can send me a push notification of the RO water level falls below 5cm. Details to follow.

Water Parameters

All tests are done using a Hanna HI97115C photometer. pH, ORP and temperature are measured via the Apex. Salinity is measured using the Hanna HI98194 and pH and temperature are verified using this meter.

Date Temp (°C) Salinity (PSU) pH Alk (dKH) Ca (ppm) Mg (ppm) NH3+NH4 (ppm) NO2- (ppm) NO3- (ppm) PO4 (ppm) ORP
29 Feb '24 25.4 32 8.0 6.9 385 1140 0.1 0 0 0.03 254
2 Mar '24 24.9 35 7.86 0.2 0 0.2 370
4 Mar '24 24.9 35 7.98 6.7 420 1370 0.15 0 1 0.1 361
5 Mar '24 0.01 (H)
6 Mar '24 24.9 7.98 -> 8.20 5.9 (S,H) -> 7.1 (S) 435 1335
2 Sep '24 25.0 34.3 8.0 - 8.3 8.3 432 370 - 400

Feeding

Feeding is twice a day using various frozen foods such as brine shrimp, spirulina mysis, emerald cuisine, PE mysis, cyclopeeze etc. I soak the food in Selco. Each day I would add some finely cut nori or seaweed extreme. For my tang I provide a small piece of nori on a Sea Veggie clip daily, alternating between the green and purple Sea Veggies.

Maintenance

Maintenance consists of 70ℓ bi-weekly water changes with 35 PSU Red Sea salt, cleaning of the glass panes, cleaning skimmer cup, and cleaning of the gyre pumps when I am up to it. I also harvest some chaeto.

Power Backup

For backup I have custom built a solution powering my Red Sea ReefRun return pump and the two ReefWave 45 wavemakers. It consists of a 12V 30Ah LiFePO4 battery driving one ReefWave 45, and a 24V 100Ah LiFePO4 driving the other ReefWave 45 and return pump. The controller is a custom built design to switch between AC and DC, and back again. Details here.

QT Tank

A 20g tank is used as quarantine for all new fish. They go in there for 21 days of observation. I do not do any pre-emptive medication, this is just for observation and allowing the fish to adapt to my water and food. The tank has an Eheim canister filter and a Jebao MLW-10 wavemaker and a 250W Jager heater. This tank is only online when I am adding new fish - currently (Sep 2024) it is in storage until needed.