Mmiller2001

It's super easy to mix dry fertilizers and I would highly recommend that route.

Well.....GDA much!

Probably low light and low CO2. What's your GH and KH? How much fertilizer are you dosing a week? There's also a specific disease this plant can suffer from.

It's 100% the rocks or gravel raising the KH. Ignore the pH, and find whatever is raising KH and remove it. Replace it with inert stone if you want to keep that look. It's a wives tale that pH fluctuations harm fish. If soft water fish are your interest, like mine, I would just run 0dKH. Forgo the mixing and just use your RO water and mineralize the RO water to 5dGH and call it a day. MgSO4 and CaSO4 are readily available and dirt cheap and I would mix 2:1 Ca:Mg.

Your tank looks great even with a bit of algae. And make no assumption, every tank has some algae regardless of CO2 or not. That said, I would encourage you to try CO2, it opens up an avenue that's not possible without it. It looks like you have a good grasp on planted tanks, and after some additional research, I'd imagine you would have one heck of a nice tank. Algae is not caused only by a lack of something, but can also be too much of something. This is usually too much light and using CO2 will allow your plants to use that extra light without an algae outbreak. Honestly, go for it. It's not complicated, it just takes a bit more research and understanding. And in my case, that's what makes this hobby fun and interesting. Trying to solve problems while injecting CO2 is very rewarding. I cringe when I see "don't chase numbers", not only will you be chasing those numbers, you're going to learn how to set those numbers. The chase will make you a better under water gardener, and you will probably "cringe" when you see similar comments with your new found knowledge. CO2art is an excellent entry level regulator and they offer nice packages as well.

Do a couple 100% percent water changes.

I would not be concerned about the pH and rainbows. This tank is Greggz's tank. It's full of rainbows and his pH is around 4.8. If your pH was 6.8, you want an injected pH around 5.8 to 5.3. If you want to read his journal, and you should, here's where you can do that. It's the main source I used to achieve my own tank. The things you will read will conflict with alot of bad advice that continues to get passed down as facts and will definitely improve your own tank. https://www.plantedtank.net/threads/greggz-120g-rainbow-fish-tank-scapecrunch-interview-1-18-2021.1020497/

I like Landen Aquasoil or pool filter sand. https://www.amazon.com/Landen-Substrate-Natural-Aquarium-Freshwater/dp/B09D758JB2/ref=sxts_rp_s1_0?crid=2BLVVUT0QBHBB&cv_ct_cx=landen+aquarium+soil&keywords=landen+aquarium+soil&pd_rd_i=B09D758JB2&pd_rd_r=5db416be-1534-4aec-8842-c25d1f2b3f83&pd_rd_w=knbAb&pd_rd_wg=1hUKC&pf_rd_p=53ef7f8b-c1cb-4ebe-8d67-39f3ca0ebaf7&pf_rd_r=WK4C357XBV98XAGWF6FN&psc=1&qid=1640447194&sprefix=landen+aq%2Caps%2C218&sr=1-1-5e1b2986-06e6-4004-a85e-73bfa3ee44fe https://www.amazon.com/gp/product/B00JJ5GXSK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I would not use carbon and the tank should not have a smell. If you are smelling something foul, something is wrong. If you use carbon, just run it for a few days and then remove it. Merry Christmas!

I would go here and click on the learn drop down option and start reading. This helped me alot when I first started. https://www.2hraquarist.com/

All I can advise is that lights matter, and you get what you pay for. Do you want to grow a planted tank that looks amazing, has room for growth and brings out the true colors of your fish? Then you will have to spend money. The problem with budgets lights is that they use white light versus individual red, green and blue lights to make white light. This always results in a yellow cast in the tank and lacks the ability to make the tank "pop". I would just use your current light and see what it will grow. If you decide to move more into growing plants, you will need to set a budget, and research those light in your budget window. Budget light: Nicrew Fluval Beamswork Current USA Many recommend the Fluval 3.0, but I can not recommend them. I've sold all of mine and it was a smart decision to do so. The above will grow tanks fine, but all have that dull yellow color cast Higher end lights Chihiros ADA Twinstar UNS Onf Flat One Just to name a few, these light are to top end, and use true RGB to create various spectrums. My progression into planted aquariums has led me to the high end category, but I was very happy with Nicrew and Current USA when I first entered the planted tank hobby.

It's the root tabs leaching into the water column. Despite what people say, "heavy root feeders" do not need root tabs and do just fine with proper water column dosing. You will just have to wait out the leaching and do large water changes. I would also crank up the CO2 and light, there's no reason to use CO2 and keep it low with those plants.

Looks like BBA.

I would try to lower it as much as your livestock would handle. Most plants appreciate lower KH.

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I would have some space to let atmosphere in. Say 1 inch along the back?

100%, you want to have excellent agitation. You want gaseous exchange to occur rapidly. O2 and CO2 are independent of each other. You want to maximize O2 and CO2, by off gassing CO2 at a rapid rate. You will have to refill your tank more often, but CO2 is cheap. https://www.2hraquarist.com/blogs/choosing-co2-why/how-to-push-the-limits-of-co2-safely

It depends on the plants you want to grow, but I'm sure that light will grow Anubias type plants and ferns.

And...too many reds... plant list will be updated tonight.

Doing, at least, 50% water changes allows you to reset nutrients in the tank, reduces organics and is an overall important component of good husbandry. You can also use the 50% changes to target nutrient ppm as you can never have more than 2 times the amount you dose. Example, if you have an aquarium and dose 10ppm of NO3 weekly, do 50% changes, you can never have more than 20ppm NO3. This is a good resource for maintaining a CO2 tank. https://www.2hraquarist.com/

I actually don't know how to do this. 🤔

Having excess nutrients does not cause algae. This has been proven many times over and Estimative Index dosing revolves around supplying excess nutrients to the tank. Light drives demand Plants demand nutrients CO2 is a nutrient CO2 is always the limiting factor in low energy tanks (in the presence of enough NPK and Micros) If demand is high, CO2 must be high If CO2 is low, demand must be low All other nutrients just need to be there. Demand must match availability, if something is unavailable-algae Excessive organics that plants don't use-algae Water changes and gravel vacuuming removes excessive organics

From my understanding, the high CEC value of aquasoil pulls carbonates from the water which causes a reduction in pH. When bacteria in the soil begin doing bacteria things, this process lowers the pH in the soil and ultimately contributes to the water pH as well.

I want to report that this maintenance day got biblical. I wish I had seen @gjcarewpost prior to starting, but I feel like a shape is forming. I will wait to post a picture, but for now; enjoy this picture of my cat that only likes me and nobody else.

Hardest thing ever! Thank you for this. Seriously!