Many small adjustments, but seemingly failed build

Hello forum!

I'm an novice, and am wildly frustrated by what I've done with my aquarium build and its outcome. I want to describe things I've tried and current parameters, so this will get lengthy. I'm not sure what direction I should head in with given water parameters and success to date, despite much toying.

I'm basically open to any ideas, but now some of the main questions are:
1) Should I stop screwing with the KH and pH?
2) What builds would work with parameters closer to my faucet if that's the route I should go?
3) Plant-friendly algae eater given my setup OR scrap the plants if there are none, and then what eater? But then again, if I stop screwing with KH/pH will I need an algae eater?

I've had a 20-gallon for 4 years, 5-gallon for a year. The 5-gallon might be a whole new thread in the future, this will be about the 20.

Population: Single female betta about a year old, 8 neon tetras 4 years to 6 months old, 2 Pristella tetras 5 years old (YAY!). I have tried snails (mystery?) repeatedly that failed to make it more than 3 months, oto catfish (20% survived 2 years maybe). The plants- I have no idea what they are really, I've attached a picture of them. I'm not that attached to them of course. Other failed mollies, female betta, male betta (so long ago), other otos.

Parameters:
Ugh.
Current parameters:
Ammonia: 0
Nitrate: 0
Nitrite: 0
pH: 7.8
dGH: 7
dKH: 6
Temperature: Room temp in summer (currently 78-80), in winter 76-78 with heater

What comes out of my faucet:
Ammonia: 0.5
Nitrate: 0
Nitrite: 0
pH: 8
dGH: 4
dKH: 2

Maintenance: Every other week I change 5 gallons (25% change). I add 46 drops pH down to EACH gallon of water I put in, also for the total water change 0.25 tsp API Seachem equilibrium, 2tsp acid buffer, 2tsp alkaline buffer. I use Tetra Aquasafe per labeling instructions as a dechlorinator and conditioner.

Filtration: The filtration is max rate AquaClear 20 with carbon and foam changed per instructions.

Rationale for treatments: I've tried using baking soda to increase carbonate hardness for my plants, BUT obviously my pH is high: hence the huge amounts of pH down - is this principle wrong, or should I in fact be able to increase dKH while keeping pH stable through increasing amounts of alkaline buffer and pH down each?. The pH down has made for a huge amount of algae (phosphates?), and the baking soda made for large swings in pH, so I transitioned to the Acid/Alkaline buffer combo to try to increase KH without increasing pH. I know how a buffer works but I thought through careful titration I could get the pH closer to 7, because I wasn't after the buffering capacity after all - I was after an increased KH. The algae is intolerable as a result of increasing pH down, without real pH change. I don't know what can eat all my algae, live with my plants, live in my small aquarium and tolerate my 7.8 pH.

I've been going up on pH down gradually to the amounts I now use to try to get my pH closer to 7 while keeping dKH HIGH for the plants where it is now (6, used to be 3-4), so there's some success, i.e. dKH is up while pH is stable, but still pH is far higher than I'd prefer.

I see a couple of routes:
- Give up on the plants, which would mean forget the dKH -> forget the alkaline and acid buffers -> focus on pH down in order to get the pH ideal and settle for low dKH
- Use different methods (what I'm not sure) to increase dKH while lowering pH
- Throw everything in the garbage
- Other ideas?

Photo link if I've done this right:


Many apologies for where I have the wrong ideas or assumptions, I do not imagine I'm an expert here. Call me out where it's wrong so I can fix it. I think all these topics have been touched on individually, but I've done a lot of searching and reading and still don't know what I should do, so forgive me where I'm asking for what's out there already. I tried.

 

I'd quit worrying about the ph and the kh. Put in a hardier plant like an Amazon sword or Java fern and see how they take off. If you like snails, I've really enjoyed my Zebra snails, fun to watch, large and cute. My kids however love the Malaysian trumpet snails. I think they overbreed but that's easily dealt with. They do churn up the substrate a lot and keep it healthy. If you're not a snail lover, maybe a peppered cory or a hillstream loach? if you stop monkeying with the ph, you may find there is less algae than you think.

 

I agree with mamachickadee. The Amazon swords are very hardy and easy to maintain. Its very normal that some oto's don't survive sadly, because when they are caught its often in the wild and with toxins.. if they don't eat after that they often perish (even if they are alive when you get them)

I don't think you should think to much about the ph either. I never did and I've never had trouble in any of my tanks and I sure have had a a lot of different ones.

I had my lights on for 7/8 hours and didnt have it close to direct sunlight (this will help to reduce algea)

But my opinion is that if you have a tank with live plants, there will be some extra work involved. There are also shripms if you want something that can eat the algae and ofc the snails mamachikadee have posted.

 

I would stop the pH Down. You are only dropping it from 8 to 7.8 so it's not worth it imo.

 

This is very good, thank you.

With these suggestions I think what I'll try decreasing BOTH the alkaline and acid buffer, and the pH down simultaneously, maybe 25% per change, and give it a shot. When I used less pH down earlier after starting to use the buffer the pH was more like 8.2, so I think I need to use less buffer while I decrease pH down. So dKH will be closer to 2, pH 8.0. If the plants start looking bad I'll pull them out and replace with java ferns and amazon swords if I can find them; local stores ain't consistently well stocked.

Anxious about my fish hanging out all the way at 8. But the build I've got ain't working that well either. So let's see.