I'm not critisizing in any way, but how much was that sump? It's looks very expensive. You aren't falling into this, but many times I see people spend several hundred on complex sumps on smaller tanks and then cheap out or completely forego C02... it's too early at the moment to be sure, but my custom made $550 regulator had at least one area that was not adequately tightened. I've gone through like 3 20lb tanks since August. I think I've got it fixed now, but just hooked up a new tank yesterday. I expect at least 4 months running both of my 75 gallon tanks. Now I feel like I should have researched and bought the pieces myself and learned the ins and outs.
On the other hand as far as function I've had no problems with my cheap (it looks like cheap crap with nearly useless gauges and a very poor needle valve) on my 150. Once I got it set it comes on and turns off and keeps flow constant and no leaks.
Lastly have you located a place to fill the tank? My local place does not fill... only exchanges. Fortunately they always keep a nice looking 5lb and 20lb aluminum tank for me. I bought my first 20lb tank on amazon for like $120... but the 5lb tank i just bought there.. it was about $100 for a filled 5lb tank. Refills are $18 for the 5lb and $32 For the 20lb. I just couldn't hide a 20lb for my 150 since it's in the entryway.
Have you gotten your ferts yet? I started with just the basic EI ferts. A few months later and I've got some serious deficiencies in Fe, Mg, and Ca. So I would get those too
I'm not really sure how to answer this as it's a little all over the place. The sump was a little over $500. It adds nearly 50g of additional capacity, but more importantly allows me to keep all of the accessories out of the tank, plus it is modular. Trying to maneuver a single 50g container into the space is darn near impossible.
The reg cost me $195 shipped, including the power supply for the solenoid. It's a Advanced Specialty Gas Equipment reg, Parker Skinner 3 watt/24 Volt Stainless Steel solenoid, and a Parker Stainless Steel metering valve. I'm pressure testing it this weekend, but I doubt there will be any issues as the whole thing looks new (even though it's not). I play paintball, so I'm pretty familiar with small air systems and regulators, and don't really care to learn the subtleties of the regulator body, especially since you can't really do anything about it if it has and internal failure. Everything else is a bolt on.
They only do swaps in my area, I looked into that before committing to a tank. 5lb is too small, they rarely have 10lbs available for swap, so 20lb it is, plus I have room for it next to the tank in a area where it won't get bumped.
Not going to worry about ferts for a while, that's part of what the ADA Amazonia is for.
Updated layout. Not massively different, but tamed the left side.
And some pics of the reg.