Mmiller2001

Looks like hair on the AR, the others I can't see well enough.

GH booster would work, the problem with most GH boosters is that they also contain potassium. So while raising GH, you also raise K. This leads to higher TDS at any given GH. I mineralize my RO to 5GH, that's around 87ish TDS. If I used Equilibrium or boosters, my TDS would be near 200. Since using just Ca/Mg, plus all my fertilizers, my tank sits at 145 TDS. My shrimp tank sits at about 180 because I add potassium carbonate to about 2dKH. When I was able to drop the TDS, my shrimp population exploded. I easily hit in the hundreds.

Small water changes with just RO is fine. Or you can blend and water change, the above will be faster, but the below is more stable. However, 10% increments is stable enough.

450 is very high and not ideal. I would just use MgSO4 and CaSO4 to raise GH. This will allow for the lowest possible TDS before adding everything else. https://greenleafaquariums.com/products/magnesium-sulfate-mgso4-1lb-bag.html https://greenleafaquariums.com/products/calcium-sulfate-caso4-1lb-bag.html

I would try to drop your TDS while maintaining a higher GH. I've found Equilibrium to be problematic when trying to keep shrimp as it increases TDS far too much. Water changes and new water parameters can force a molt. But the shrimp should be out and about. All of my shrimp are very active even with fish present.

Ammonia source, remove them.

Hiting a 6.8 pH with a 12dKH is going to be difficult. What are your stocking plans?

I would forgo the light siesta and just start everything later in the day. Otherwise, you are on track. I know other people run their air stone 10 minutes every hour while CO2 is running.

Finnex ALC's are a great choice. I've sold all but 1 Fluval 3.0 and will be selling the 36 inch Fluval soon. I'm torn between another Finnex or trying Current USA's new light https://current-usa.com/serene-sun-le-pro-led-light/ They are boasting 65 PAR at 24 inches. If you have a bigger budget, look at the Chihiros WRGB II 120. Love mine.

https://greenleafaquariums.com/products/potassium-sulfate-k2so4-1lb-bag.html

There are several products you could use such as Seachem Potassium or K2SO4 powder. As far as shells are concerned, that's probably more related to calcium issues. Some products have both Ca, Mg, K and Fe. Seachem Equilibrium contains these elements and might be an option for you. K2SO4 would be the most cost effective option and is easy to measure.

I would increase surface agitation as much as possible. You want to maximize gaseous exchange for both CO2 and O2. Here's my surface agitation and I also surface skim the tank. https://youtu.be/7oCxiKw3ZyU

I use garlic guard. Seems to do the trick when using medicine.

I would use a product like Seachem Alkalinity. You want to raise KH.

Maybe it's the altitude I'm at? When I used an inline diffuser, I think I only got 45ish days out of my tank. Now a days, I have double surface skimming and more surface agitation. I'm also at peak injection faster than before. This could explain things.

What's your injection method?

CO2 doesn't kill algae directly, but lowering light could stretch your CO2 usage.

On a 75 gallon tank, you might have to fill too often making it a chore. I go through a 10lb tank about every 35 days on my 75. I would spend the extra bucks, get something like a CO2Art regulator or GLA regulator and use the 10lb tank.

Have you researched the potential down side of single stage regulators? FYI, dual stage prevent end of tank dump. It might be better to exchange it for a dual stage option.

I would say no.

1. Lobelia Cardinalis 2. Persecaria Kawagoeanum 3. Ludwigia Ovalis Pink 4. Barclaya Longifolia 5. Purple Repens 6. Pogostemon Erectus 7. Bacopa Colorata 8. Alternanthera Reineckii mini 9. Myriophyllum Roraima 10. Juncus Repens 11. Bacopa Salzmanni purple 12. Pogostemon Helferi 'Downoi' 13. Ludwigia Peruensis/Gladulosa var. Diamond 14. Pogoestomon Kimberly 15. Rotala Bonsai 16. Nymphoides Hydrophylla 'Taiwan' 17. Lindernia India 18. Ludwigia Natans Super Red 19. Bacopa Salzmanni 20. Limnophila Vietnam 21. Syngonanthus Belem 22. Limnophila Aromatica mini @anewbie @Patrick_G

Any chance you could circle them?

If you want to maintain a checker, go with @CT_ type. But truth is, they aren't the greatest, and I would use the pH drop method to really set CO2 levels. You want to measure a 1 to 1.5pH drop from degassed water to peak injection. Take a sample of your water and let it sit for 24 hours. PH it. That's your degassed measurement, then pH the tank when injection has been running for at least 2 hours. My degassed is 7 to 6.8pH, my peak injection is a 5.1 to 5.3pH. A one point drop puts you right at 30ppm. But you will see you can push more as other influences lower pH too. So get to 1pH drop, then if you push any more, definitely watch your fish for any problems.

Thank you!

This is the only unsolicited advice I will give you. Step out of your comfort zone and try plants that are considered more challenging, it's well worth it!