Don't get too excited by the great sounding Title
Nothing scientific from me of course, but two examples may help illustrate some common issues. Please forgive the length in advance...
I have a 57 gal that has an Eheim pro II G90 (2075 - 280gph) for flow and filtration using an Up Aqua atomizer for c02. I use a spraybar and flow goes from right to left. Over several weeks time, the plants on the RECEIVING end of the flow were MUCH more robust and lush than the other side, where hardly ANY new growth had occured. Blyxa on the left, and Java on the right.
This went on for several weeks and the left side was like a giant and an ant in comparison. It was painfully obvious there was an issue
I installed an MP10 on the left side pointing right. Within 2-3 days, the right side and middle, back areas had more growth than the previous two weeks, well seemed like it anyway...After 1 week, growth was MUCH improved in all areas of the tank.
I have since installed another 2075 canister from the other side that provides a really nice surface ripple and counter flow. The MP10 is used mid-water/back to get the stems..
Is my 220. A few months back I replaced my twin DIY NW rio 1k pumps with a SINGLE inline NW pump. While it may provide the same C02 content, I lost almost 2k gph by the removal of the twin IN-TANK pumps...At the same time, I introduced a lot of small surface dwelling fish, so the MP40 was turned very low to avoid any stress.
I have twin Pro III 2080 (450 gph) on this and an MP40 as well. The one canister has the NW inline and uses a spraybar to help distribute the c02, and the other canister does NOT use a bar, and is used for surface agitation. The MP40 is behind the c02 flow and pushes it around.
I noticed that SOME plants did well but not all. At the same time, the pencils got stronger/bigger. About a week ago, I started turning up the MP40 flow and I can see a big difference, esp in my beloved anubias coffeefolia. I can really see plant movement/sway all over, but the fish are fine with it. They have areas of quieter waters they can shoal in. I still have plenty available from the MP40...
So, I made no other changes to c02 or dosing or lighting at this time. Just increased and improved FLOW and DISTRIBUTION.
Part II concerns surface ripple.
In my 220, I noticed the fish were breathing rapidly in the morning, many hours after c02 was off. I also noticed that I had removed almost all surface ripple for the pencils. I took one of the old rio nw pumps and placed it on one end and let it rip at the surface. Within 10 minutes, the fish were breathing much more normally. It provides a really nice ripple but of course is visible...
I have since timed this for 20 minutes PRIOR to c02 on, and then 1 hour AFTER c02 is off to degas. Since then, the fish are more active during c02 times, and no more rapid breathing in the am.
The 57 gal had times when c02 was off for many hours, but the fish were acting like c02 was high. I used a rio 180 for surface ripple and it made a big difference after that.
I think the combination of canister filters and no surface ripple, along with c02, was building up over time. With no surface agitation, 02 was in shorter supply.
I have to say that I think this may have been the final piece of my specific growth issues. Most stuff is fine, but some random growth issues, made no sense.
Looking back, I removed flow and surface agitation in my desire to eliminate in tank hardware but at the cost of good c02 distribution and the addition of 02 from the surface.
In the 2 weeks since I have made these changes, it has made a marked and observable difference in plant growth and health, as well as fish health.
I may have had plenty of c02, but it wasn't getting everywhere it should have in the quantities needed.
The fish are not overwhelmed with the flow (we observe and adjust just like for c02) and the plants definitely are responding favorably. The coffeefolia is really doing much better, and the clover areas recently trimmed are recovering more rapidly and densely.
Very happy overall. Pics soon I hope once all regrowth is done. 7-10 days max I hope, both tanks will look really nice.
In both case, it seems like overflow (ha ha), but in reality the cardinals in the 57 are really happy, and the pencils in the 220 are doing very well indeed. I really encourage all to take the higher turnover rates seriously. You may have enough, but may also not be routed optimally.
Best thing is I did no other changes in either tank, so was fairly easy to see an apparent cause and effect
Hope this helps.