A twist on the under gravel jets idea.
Hello all. I am new to the forum and was wondering if anyone has built an under gravel jet system with random holes drilled into the PVC tubing, similar to a an Eheim spray bar, instead of just a few jets. I am talking about the PVC buried in the gravel the same as the UGJ, not near the surface of the tank. I built one yesterday but am not sure what size holes to drill, I don't want too much pressure or too little either. I took the assembly outside and connected it to a garden hose and got what would be probably too much flow for the fish. It would be great if it would fit in the bathtub but my tank is a 125 gallon and the assembly is too long. The faucet outside is far different from the flow from my pump so that probably wasn't a good test. I found a number 29 drill bit, 0.136 inch, to be a perfict fit in my Eheim spray bar so I drilled about 40 holes with a number 46 bit which is 0.081 inch. My reasoning is that the Eheim spray bar only has 9 holes so I went with a much smaller drill bit so tht I could drill holes ever 4-6 inches in the PVC. I built this to go around the perimiter of the tank with 2 tees and 2 short sections of pipe front to back. The pump is a Rio 2100+ which, according to the box is 692 gph. I don't want this to be a trial and error affair because my fish are in the tank and I don't want to scare them any more than necessary. Does anyone have any ideas or experience with this? Thanks.:help: