Finally, I get to make one of these tank journals after getting my fish tank. The fish tank is about 120 gallons 72" X 16" X 24". It was custom made and is all glass. The inside of the tank is not great so I will be resealing the tank. I plan to make this a planted discus tank. I'm going to go at this build one step at a time, starting with resealing the tank first then drill holes for an overflow + sump. Overall, i'm pretty excited to start with a large tank with fish I love. I think the sump will be 29 gallons but not sure if I can fit a 40 gallon breeder tank under a 16 wide tank. If I find a way I will.

I will work on setting up the planted tank first and learning how to care for it. After I get the routine down I will be getting six discus. The new comers will have their own tank to grow out probably to 5" or 4" before being moved to the planted tank. The size of the tank will at least be above 60 gallons but i'll let craigslist decide on that . It will be a bare bottom for easy clean up with sponge filter and heater. I am not sure on the growth rate of a discus but hopefully it will not be too long (1 year+) before they get to a good size.

What I know so far:
Fish list:
6 X Discus (Three pairs)
15 X Cardinal Tetra
10 X Sterbai Cory
10 X Marbled Hatchet Fish
Algae / clean up crew: ?

Plants:
South American plants - I know some from tropica but would like some reds too.

Light:
Moderate level

Substrate:
Pool Filter Sand

CO2:
Yes, but will come at a later time when I get the plants in the tank. Do not want to have a high level of CO2 but just enough to have a moderate growth. Not sure if I should go with DIY or Pressurized CO2

Filter:
Sponge filters

Picture of the tank:

Attached Thumbnails

 

As you well know my friend, your approach to discus-keeping has been well researched and thought out, and is a safe strategy for being successful keeping them healthy and thriving.
All the best to you - we'll look forward to seeing & hearing of further developments !

Update:
I washed the tank and now its nice and clean with no sand. I did some scrubbing with a soft sponge and salt to remove hard water but there is a little bit left. A small razor blade will fix that. The next thing to do is reseal it and then start drilling. I double checked the tank to confirm glass with laptop screen and sunglasses, and the panel I am drilling is glass! While I was drying the tank with alcohol I found a spot on the side of the tank that got chipped. Its a shallow dent, I don't think will destroy the integrity of the tank. The down side is that the previous owners silicone over the chip. I think I might need to remove it to fix it with maybe a windshield fixer. Do you guys think I should leave it alone?

Update:
Got the Momentive RTV - 108 from Amazon on Friday. Applied the silicone today on the tank and it was a mess. I wasn't aware there was a aluminum seal inside the tube. I couldn't get it to dispense until I bent the caulk gun a bit. Once I figured out there was a seal. I broke the seal and the rest was a breeze. The second tube was a complete disaster. I made a mistake and put too much pressure on the scissor to pierce the aluminum seal. In the process split the tip of the tube. I applied the silicone the best I could. After finishing the reseal I compared the two different situation. The first time with an intact tip did a better job at sealing with no micro bubbles at all. The tip that had the split tip had a ton of micro-bubbles probably from scooping up excess silicone and working it into a messy rectangular pile to smash into the edge which led to tons of microbubbles. I'm gonna have to reorder new silicone and redo the seal on the tank.

Update:
I just finished removing silicone residue leftover from the silicone seal. It wasn't fun but I got to job done. I found it easy to scrap it off with a razor blade a couple of times then going over the area with alcohol. The alcohol got rid of smears from silicone bits in order to see if any residue remains. I plan to lay green tape and silicone down tomorrow. This time it'll go right because I learned from my mistakes the first time. I can't wait to get on to drilling holes and building a solid tank stand then comes plumbing!

Laying silicone is best learned through practice. I made a lot of mistakes, but learned lots of lessons. Start with a small bead (as even as possible). Then smooth the bead with a fingertip dipped in isopropyl alcohol. Pay no attention to the silicone that spreads outside your target area. Trying to clean it up while it is wet just creates a mess. Dip and clean your finger in alcohol before each smoothing pass. Once you have a clean fillet then just let it dry. Do not try and cleanup before it is completely cured. I find that the best way to clean up is to use a piece of wood that is the thickness of your desired fillet radius. Usually 1/4 to 3/8 inches. Use a standard single edge razor blade (not a pointed blade used in Stanley knives). Place the blade flush against the wood and scribe a cut in the dried silicone. Now that you have your cut done, reposition your blade so that the side of the blade is against the same piece of wood (perpendicular). At this point you can slide the wood and blade down the corner to remove any excess. It is important that you do not cut under the edge of the fillet, as this will create pockets where algae will grow and make your seam look unsightly.

DIY CO2 can create more problems than help. The flow is never consistent and will fluctuate between bottle changes. The only way to truly maintain consistent CO2 is with a pressurized system.

@AguaScape
I bought a silicone kit from home depot. The price wasn't bad at all for 12$. The thickness of my glass is like 1/2". The silicone finisher I plan to use will 16 mm. I will definitely use a smaller line of silicone like you recommend, so there is not a large amount of excess. I did buy three tubes of silicone this time so if a mistake does happen there is a back up. Instead of using masking tape I will use painter's tape that is green and wider compared to the masking tape. I might do two rows of them to reduce stray silicone splotches and make a tab at the ends. The tab would serve as an easy starting point to peel the tape off instead of the first time which was frustrating. I was chatting to a friend about my silicone experience. He recommended I get a filter mask at harbor freight. I might do this because the fumes were unpleasant and would help me focus on the work. I will also need to buy a wind shield repair kit to fix my chip I found on the side of the tank. I am hopeful it will work because I saw a repair done on YouTube.

For the CO2 aspect of my tank I think I will be going with pressurize CO2. The amount of CO2 in a tank and only refilling it up every couple of months is appealing. I wasn't aware of the fact that CO2 flow was inconsistent with a DIY CO2 so that's nice to know now. The only fear I have about pressurize CO2 is gassing my tank and killing expensive discus fish. I want to look more into a pressurize system and see if there are any safe guards that exist. If anyone has safe guards for their CO2 system I would like to know . I know I haven't done too much reading into pressurized CO2 but will get there eventually. I have read into a thread about DIY CO2 system and that sounds appealing because buying individual parts is nice for the wallet. I also like seeing which parts not to skimp on and which brands of a part can get the job done reliably.

Today, I found out that BBA can appear when CO2 is inconsistent so that is interesting. I would also like to try my best to avoid BBA. I think I read somewhere that they can appear when you are injecting CO2 and the levels are inconsistent. So how do CO2 levels get inconsistent in the first place?

The bead you are applying is larger than I was thinking, but with 1/2" glass it sounds about right. Using painter's tape is probably the best way to go with a larger bead. having too little is worse than having a bit too much as you can get air pockets if there is not enough to spread evenly. Good idea on the tabs. Just make sure they are not near the tooling area. Yeah. A lot of silicone in an enclosed space like a tank is very unpleasant. I highly recommend a good mask. Good air circulation is needed as well.

DIY CO2 depends on a chemical or yeast reaction that works good for awhile and then tapers off as the sugar or chemicals get depleted. The best safeguard for pressurized CO2 is a PH controller. I just got one recently and I wish I had earlier. They are not cheap, but when you compare the cost to the financial and emotional investment of Discus, it is really pretty cheap. The Milwaukee one runs about $130. The American Marine Pinpoint is almost $200. Worth every penny IMO as it takes all the guesswork out of it. CO2 stops when your PH reaches a set point. There is a new kid on the block that is cheaper, but I have not seen anyone using it yet and the reviews are worrisome. I hesitate to recommend a product that does not have a good track record yet. What I did was to buy a used American Marine Pinpoint and a new probe kit. Cost me $110 total.

Yep. I found out about BBA the hard way. My tank ran empty and I did not realize it until I noticed BBA popping up. There is definitely a connection there.

@AguaScape
I am positive I proof read my post and it sounded right at that moment. I am reading this now after a nice long sleep with coffee and I am positive I mistaken DIY CO2 for DIY CO2 Regulator lol. I am skimming through advanceplantedtank in their Plantedtank 101. I saw a CO2 reactor is a tool hobbyist can use that can inject CO2 efficiently. They have a higher efficiency compared to the other two options which are fine CO2 bubblers and inline atomizers. I will look into how to build a CO2 reactor or just purchase one online if it is durable and affordable when the time comes. My overall plan is to get the planted tank fine tune so no tinkering and accidents happen while fish are present. The plants and decor will be there of course so I can observe the effects of fine tuning my system. I am not sure if I can add a clean up crew while I fine tune CO2. I have concerns about bringing contaminants via snail or shrimps before the discus get released in the display tank.

I wasn't aware of the fact that pH probes could be a safeguard for CO2 injections. I am liking the cheaper one only because I see that it has what I consider a safeguard. It controls the on and off switch for CO2 injection should it go out of parameter set by the owner. The other two do not look like it does the same thing and alerts by changing an LED light or something. The concern I have is if the 70$ is a quality product. No point in going with the cheaper one if the pH measuring system craps out then the safeguard feature is useless. Another option I can think of is if I tinker with an arduino system to get the same feature as a 70$ but with a quality probe. I would want to weigh the cost + time versus just buying the 70$ one. I'm not sure if the parts for arduino are there to make a pH probe like the 70$. I might be complicating this but its a fun thought and it would make me sleep easier.

If I do get BBA i'll be sad however it'll be an opportunity to get a sample while I destroy the rest. I'd like to see what makes them appear or see if I can kill them by adjusting a parameter. An alternative would be to see if there are any articles on them that answer my questions. I'll just wait and see if I get them. There is no need to jump the gun and go down a rabbit hole.

Haha. Yeah, there is a big difference between DIY Regulators and DIY CO2. I believe that a person with moderate skills can put together a regulator assembly that is far superior to anything that can be bought on the open market. DIY Regulators are my kind of thing. If you read this article you will see what I mean. The first half is my learning process. Many members here helped me understand the concepts. The second half is just me showing off what I have learned. There are several side tracks along the way. Go to the last page if you just want to see my latest build. I am really proud of how that one came out.

There are a lot of people here who have built some great reactors. I am going to be building a couple Variable Velocity Reactors similar to the one that @Ken Keating1 created. His amazing tank journal is here. His reactor design is covered in the first few pages.

All the ones I linked are PH controllers. Don't mistake PH controllers for PH probes or monitors since the probes and monitors cannot control your CO2 system. I have not seen anyone post up about the cheap one here. The other two I linked have been used by members for years with glowing recommendations. There is one member who has used the American Marine Pinpoint for 10 years with no problems.

I personally have not dived into Arduinos yet as I know I myself and I don't need another rabbit hole at this time.

BBA happens. I did not have it until my CO2 ran out and I was not aware of it. Another good thing about a controller is that it is easier to notice that you are out of CO2. I just happened to look at my controller today and noticed that my PH was close to 7 and it is set at 6.8. I immediately checked my tank and it was empty. If I did not have the controller right there where I can easily see what is going on, I may have not noticed. Crisis narrowly averted. I do not want to have to fight that battle again so soon. On the bright side it gave me a chance to put my new reg through it's paces. It was already hooked up to my second tank.

Update:
I finished resealing the tank today. A majority of the edges look great except for this one small segment in the back of the tank. There are a couple of tiny bubbles but not any gigantic. Its a huge improvement compared to the first time applying silicone. I think its good enough and will move on to a tank stand and lights. I plan to just use a stand calculator to plan my stand then skin it with plywood. The lights I am planning to do DIY. Plan for pressurized CO2 but its a step ahead.