Pump update: Overkill
I have replaced the OEM AquaClear 20 with... something ridiculous. A Fluval 306 external canister. Let me explain.
I got the filter back on Black Friday for just $85 on a Petco website error. I had no immediate need for it, but have been piecing together the stuff I need for bigger tank, and it was a killer deal. It's been in my basement ever since.
Fast forward to today. I've been battling algae, which is mostly CO2 related. The DIY CO2 is inconstant. I think it's mostly due to my house temp which is run on a programmable thermostat. In the winter the drops to 62 during the day and at night and it runs at 69 in the morning and evenings. CO2 output drops noticeably when the temp drops to 62.
The other issue that is causing algae (I think) is flow. The AC 20 filter really doesn't move the water that well now that the tank is filled with plants. Almost all of the algae is where there is almost no flow. Furthermore, CO2 bubbles on the top of this tank bugs me.
I've been thinking of adding an external pump to improve flow, and then I could also hook a C02 reactor to it and get rid of the bubbles. Win! Except that there is no room for hoses with the AC20 in the way, or I'd at least have to re-do my whole custom light thing, and I don't even know if I can fit the hoses anyway. I've literally been thinking about this for weeks.
Then today it dawned on my that I had this big canister filter that could theoretically solve the problem. The issue was could I get it to run slow enough. The manual even says you can slow it down as much as you want with no harm or extra wear on the motor. Well the answer is YES! I can literally slow it down to nothing, or crank it up to a full 300+ GPH (EEK!).
After thorough testing, I made the swap tonight. I love that I can aim the output of this thing to move water however I want. I'm quite happy with everything other than cosmetics. I don't like how the included intake/output look in the tank. Oh well, I can deal with that later.
Hoses route pretty easily through the back:
No problem fitting behind my light (in fact there is quite a bit more room here now):
Here's the part I'm not in love with, the bright white equipment:
In all, I'm digging it. I can adjust the output to push anywhere, and I can adjust the flow volume very easily. I can now hook up a hydor inline heater and a CO2 reactor and get those two things out of my tank, so that's nice as well.