Hi Monis,I think I have a decent flow as I can see that the leaves are gently swaying. The spray bar runs accross the tank and has 6 holes roughly 1/8" diameter. Is there a way to test if the flow is a complete circular motion by adding something to the tank?
Yes, you can cut a tiny piece of paper, perhaps pin-head size, and drop it on the surface, then watch it's path through the water. This will show you the general flow field that the spraybars create. Do this at as many locations as you want along the length of the tank (middle, corners and so forth). What you hope to see is that the paper heads toward the front glass hand heads rapidly downward along that front pane, then it should head towards the rear and then up along the rear pane. Of course, the speed will peter out and it may start to drift away from this ideal path, but you'd like to see it last at least half way towards the rear.
In this way you will be able to visualize the flow. This technique is not dissimilar to what is done in a wind tunnels using smoke to visualize air flow around an object such as an automobile or airplane.
I highly recommend to anyone injecting CO2 to invest in a quality pH probe and pH probe calibration solution. It never ceases to amaze me how many posts I see where the hobbyists is giddy at the thought of spending megabucks on some fancy high powered light (which ironically is the root of all evil) and yet never give a thought to spending money on a good pH probe. Your money should always be spent first and foremost on CO2 problem solving because about 95% of all problems in a CO2 injected tank is due to poor CO2. Let that sink in for a moment... CO2 is always problematic and even if it's perfect today it's a sure thing that it will be somewhere between imperfect and catastrophic a month from now. I suggest investing in any of Hanna's multi-probe such as their pH/TDS/Temp probe.following was the pH profile measured by API Drop Test Kit:
It's difficult to comment on the yellow DC as there are so many factors such as what kind of water is placed in the DC, accuracy of the reagent and so forth.