For your substrate, yes, I do think it will cause an issue with the juvenile discus development, especially with how deep it is and especially since you have larger gravel underneath the finer sand. Even though the sand is fine and appears to only have detritus sit on top, it doesn’t. The detritus will get down into the sand and will foul the water too quickly for what the juvenile discus need. You just won’t be able to see it like you can on a bare bottom tank. The same goes for the plants and driftwood, although those are easier to get in and clean out during water changes, so I can see them being ok if proper maintenance is done.
You are definitely on the right track of narrowing down the ones you keep as time goes along, provided the tank size stays the same. If going to a bigger tank like a 125, then you’ll be fine to keep them all.
As for the pleco, the two main problems are it dirtying the water because they have a heavy bioload and if it gets the taste for discus slime coat. The dirty fish part won’t go away and it will not be 2” for very long. The bigger it grows, the bigger it’s bioload will be and the worse it will be for growing discus. The slime coat eating is not a for sure thing, but if it happens, the pleco can do a lot of damage in a short amount of time. Even if it spreads its attacks out across the group, each fish will be stressed and prone to infection and may never fully recover. It’s best to get rid of it and combat algae with proper water changes, tank maintenance, and plant nutrition. Look into what your plants need to flourish, but be very careful if you decide to run co2 because discus are very sensitive to it and can easily be suffocated. Also be careful in what you add for the plant nutrition because it all affects the water quality and can have adverse effects on the discus.
For the water changes, yes, I absolutely think 50-75% is necessary for juvenile discus under 4-5”. People telling you otherwise either never dealt with growing out discus or they have poor quality and unhealthy ones. Once they get over the 5” mark, then the water changes can begin to slow down, as long as the water quality remains up to par. Discus over 5” are far more hardy than those under.
For the filtration and water changes, the amount of filtration has nothing to do with the number of necessary water changes. You can have 25 FX6’s on the tank and the waste produced will still be the same, which will still require the same amount of water changes. This again comes down to your decision to get not just juveniles, but very young 2” juveniles. They are extremely sensitive to the amount of nitrates and TDS in the water...much more so than any other fish I know of. This is why they need water changes so often. If you do not keep up with these water changes then it will cause the fish to become stunted and unhealthy, which will be irreversible damage to the fish’s wellbeing. This is also why the substrate and decor are bad ideas for growing out discus. They hold detritus that increases nitrates and TDS in the tank.
For the other dither fish, they would be fine if the tank were bigger. However, with the size of the tank and the number of discus you’re getting, I highly recommend going with the discus only. They are a very skittish fish that is easily stressed out, even by smaller fish.
The powerheads should be removed. The filters themselves provide plenty of flow to keep the tank healthy and discus have a physical build that makes them unable to handle high flow situations very well. Again, this will add to their stress, which will cause them to become unhealthy and stunted. Instead of relying on flow to keep the tank “clean” you will need to use the gravel vac to suck out any detritus you see settled on the bottom of the tank whenever you’re doing a water change, sometimes even in between water changes. Along with this, make sure you do filter maintenance a few times a week. The detritus that gets caught in the filters is still putting waste into the aquarium until it is removed.
To touch on ph again, you will definitely be fine with your tap water as long as you treat it with prime. It would help to age it and preheat it in a barrel or brute trash can for at least 24 hours beforehand, but it’s not required. You can certainly go the RO water route, but make sure you are using a supplement that will remineralize the water afterwards. They make supplements specifically for discus. Either way you decide to go, don’t go chasing ph. Just be consistent and the discus will be fine. They are much more sensitive to ph swings because you’re chasing that correct ph than they are to higher ph levels. Discus Hans uses just tap water and he has some of the best discus in the industry. I remember hearing that the ph of the water he uses is at or over 8.0.
This is all knowledge I have gained looking into discus for years. I am a member on the Simply Discus forum and have spent countless hours reading on that forum about discus care. That is an entire forum that is for only discus. I have not bought discus for myself yet because I do not have the time or money to care for them properly since I have a family, house, full-time job, take evening classes, etc.
I see two routes for you to go here if you want healthy, large, colorful discus. First, you can take the advice I’ve given you and convert your tank (or get another one) into a bare bottom growout tank and do the necessary water changes until the discus are grown and can be moved into a scaped tank. Or, the second option is to cancel the order for the juvenile discus and instead order six larger discus that are 5” or bigger.
There is a reason why the larger discus cost so much money. It’s because of the care it takes to get them there. They require many many many water changes and a lot of time siphoning the bottom of the tank. If they only required a 50% water change once a week in a scaped tank then the adult fish would be way cheaper.
I’m truly not trying to be difficult, I am just trying to be real with you so that you are setup for success and not failure. I’ve seen a ton of threads over on Simply Discus where people start exactly like you’re describing and then come to the forum because their fish keep dying or won’t grow. Then, when people over their tell them what they’re doing wrong and how to do things right, often times they come back with stuff like “the guy at my LFS said all I needed was to do a 50% water change once a month.” Often times they don’t believe the forum members and often times they lose most or all of their fish.
I truly wish you the best of luck with your discus endeavor and hope to see some beautiful pictures of them. They are definitely one of my absolute favorite fish.
let me guess the person selling it to you told you that! Lol. Such a falicy. If you like plecos as a fish they can be fun, I love them and have a small collection of them happening. But as for them being cleaners, not very likely. Check out some of the pleco section stickies to learn more about pleco behaviour. Some of the messiest fish I have ever had next to the rays.
