Time to get a new journal started. The start of this aquarium will eventually result in the total rescape of some and even final end to others.
So why is 75g in quotes? It seems that the budget pet store aquarium brands like to over state the volume of their tanks. This is a used Marineland tank and stand combo I purchased off marketplace. Marineland markets it as a 75 gallon tank. At best, it's only a 67 gallon tank. Filled with BDBS and including the volume of the filter, tubing, and reactor, real volume is just over 64 gallons. End of rant, now the details.
This tank has a number of purposes/goals:
1. Serve as a tank to grow many different plants.
2. Serve as a temporary holding tank for fish.
3. Serve as a testbed for my first fully inert substrate tank with water column dosing only, using separate macros and micros rather than an all-in-one fertilizer.
4. Try my hand at designing and maintaining a Garden/Hybrid Dutch style layout.
I began getting this tank and stand ready quite some time ago but other projects got in the way. Like my current 40g farm tank, this is setup on the "work" side of my basement. The other side of the basement was finished when I purchased the house but it was done rather poorly and has been in mid demo mode for some time. It will eventually be remodeled to be the aquarium "gallery". Once that happens, this tank may simply become a farm/quarantine tank. My basement floor is far from level so I had to add leveling feet to the stand. I soon realized however, the bottom of the cheap stand is only 1/2" wood?? and with the resulting gap underneath, the weight of an Oase 850 filter and 10lb CO2 tank caused the bottom to flex a good amount. I decided I needed to make some mods to provide a little more support. I added a sheet of 3/4" plywood across the entire bottom including the finishing strips. I used a lot of wood glue and brads to secure it and then upgraded to some heavier duty leveling feet.. That did the trick as it's much more solid now. While I had the stand up on the saw horses I also made a few changes to the inside build. I swapped out the dosing bottle holder to a powered stirrer courtesy of a great deal from
@Naturescapes_Rocco, mounted the Dwyer flow meter where it can be easily read, mounted the new Jebao return pump controller to the door, and cleaned up the wiring.
Build and Hardware Details
Oase Biomaster Thermo 850 (internal impeller disabled)
Oase stock In/Out pipes using spraybar
Oase Crystalskim 350 Skimmer
Jebao MDP-3500 Return Pump
10lb CO2 tank with DIY "Bettatail" regulator and Dwyer RMA-151 Flow Meter
Aqua Rocks Colorado Small Acrylic Yugang CO2 Reactor
Chihiros 4 Channel Doser plus Stirrer
Inkbird ITC-306A Temp Controller
Week Aqua L1200 Light
Substrate and Fertilization
Black Diamond Blasting Sand (no root tabs or other material under the BDBS)
Burr Aqua Macros and Micros
There were a couple of gotchas in the last 2 days getting things finalized so the tank can start cycling. Yesterday while calibrating the doser, I couldn't get any channel to prime. This doser has been sitting on the shelf for quite some time but had been used before. I had to take apart the pump heads and pinch and stretch the tubing, and after putting it back together, everything worked fine and calibration was right on the first time.
The worse gotcha was today on the first turn on and leak test. It's always the nervous time, and for good reason. Priming the system went fine, no leaks, but as soon as I turned the pump on, I heard spraying

! Problem was with the ARC reactor. I purchased the reactor a long time ago but realized it was too large for my 49g tank, so It's been sitting on the shelf waiting for one of these 120cm tanks. Unfortunately, I never even leak tested it. I wish I had, because I might have returned it to ARC. The problem is with the CO2 input. There is the push-to-fit part that screws in, and then the permanent mounted insert the fitting screws into. That permanent insert was actually the cause of the leak. After pulling everything back out of the cabinet and taking the reactor apart, I could see that the insert was cracked. For now, I've bypassed the reactor so the tank cycling can commence. This was important because several trays of matrix in the filter came from my other established tanks and I also seeded the tank with a sponge from one of the established filters. Over the next couple week, I'll get the ARC reactor fixed and back in place.
Also in the next couple weeks I'll do some flow testing and provide results for those curious as to how combining the Jebao pump with the Oase filter works out. I can tell you this already, in a 120cm tank, 100% power is far too much. Pulling water through the fully setup 850 doesn't faze the MDP-3500. I have it set at 55% right now and even with a spraybar, will probably need to turn it down once planted. I think the MDP-2500 would be more than enough for this setup. In fact, I may add a bypass to the ARC reactor while I have it out. Of course, it's also very quiet, even at the 100% power level.
I expect the tank to cycle fairly quickly and may start planting in a couple weeks. Most plants will come from my farm and other tanks for now, but I'll be thinking about what other plants I need to fill in for a proper Dutch look. The current 40g farm tank will be shutting down and going by-by once this tank is cycled. Also, my first aquascape, the 49g, will be getting torn down for a full rescape shortly after and the fish in it will be getting rehomed to this tank for the immediate future.