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  • venturi not working properly

    Hey all,

    I recently changed from my external DIY reactor to the venturi reactor.

    I followed exactly the diagram in the gallery.

    my tank size is 36x18x18"

    I placed the reactor near the center rear bottom of the tank...with a spraybar spraying towards the backwall of the tank..

    the bubbles do not go around the tank as it is suppose to...the mist only makes it half way to the front and then it goes to the surface.

    i've tried spraying it towards the front of the reactor, and the opposite happens, most of the mist escapes through the back of the spraybar.

    the mist also concentrates near the center and rarely makes it to the left side nor right side of the tank

    i am feeding more CO2 in the venturi than my DIY reactor, and I am experiencing thread algae all over and my pellia are all dead.

    What am I doing wrong? Hopefully I don't need to convert to the diffuser method since I thought the venturi is just as good.

    Thanks for your help.

  • #2
    Re: venturi not working properly

    I would place the spray vertically.
    Then place the Venturi reactor near the bottom directly in the path of the current.

    The mist coming out of the bottom of reactor should get swept away and be dispersed all over the tank.

    If not, wait till the end of the day and watch.

    Regards,
    Tom Barr
    www.BarrReport.com

    Comment


    • #3
      Re: venturi not working properly

      Hey Tom,

      I've tried placing the spraybar vertically down...the problem with that is the powerhead of the venturi is in the way...so there is less current since most of the current is being blocked by the powerhead.

      Comment


      • #4
        Re: venturi not working properly

        i have same setup in one of my tanks. set your reactor just behind spraybar as close to bottom as possible.outlet water will pull small bubbles from reactor.also it helps to have inlet at opposite end of tank to help pull water flow.set a powerhead at same end of reactor position just below suface to get motion and help distribute bubbles.regards,cornhusker

        Comment


        • #5
          Re: venturi not working properly

          This is the result after a week:

          CO2 is still low. I don't get BBA anymore but I'm getting quite a lot of thread algae and GSA on the glass (even with high PO4)

          My CO2 bubble rate is about 2.5-3 bubbles/sec (I just eye it)
          And this amount is already alot for a 50G tank...I don't want to increase it any further because I am refilling my 10lb CO2 tank like every 3months already.

          I know my bubble rate is enough, and my venturi is made the same way as the one in the gallery.

          So what is the problem?

          I have a spraybar that is spraying vertically down, even though 1/4 of the current is blocked out by the powerhead of the venturi. The venturi is located as far down as possible, almost touching the substrate.

          When I first had this setup, I did not have my second spraybar setup for surface movement. My fishes were surfacing really badly. But after I setup the surface movement, the fishes no longer surface anymore (they don't even gasp that hard either) and I did not change the bubble rate for the CO2.

          So does that mean I have too much surface movement? will that cause a problem?

          Thanks.

          Comment


          • #6
            Re: venturi not working properly

            No, the Surface movement is fine now.
            What you need to do is have the CO2 mist coming out the bottom shoot around the tank in a better pattern.

            You simply need to try and play around till you see the bubbles making it to most of the tank's location.

            There is no simple hard and fast description of this, just adjust and watch where they go. It's okay if the bubbles do not go "everywhere" but most places(60-100%)

            Variations in the planting, scaping, tank sizing etc makes it hard to account for it. But your CO2 is up, but not all the way yet.

            1-2 bubbles a second typically will di it for such a tank.
            Solenoid for less loss and reduced tank refills will also help.

            Regards,
            Tom Barr
            www.BarrReport.com

            Comment


            • #7
              Re: venturi not working properly

              Tom, gasping is fine if its not at the surface since you mention his CO2 is not all the way yet?

              Regards
              Peter Gwee

              Comment


              • #8
                Re: venturi not working properly

                No, they should never gasp.

                I have tested the surface movement thing 4 times lately and each time they came up with no change in either the CO2 bubble rate nor the pH.

                So the entire night time aeration thing: BS.

                But I already knew that but after seeing it to make sure a few times, now is war:-)

                I'm on a bit of warpath lately anyhow on the ADA product line, I like the soil, tanks(not the little ones, can do much much better $$ wise), some glassware.
                Most of the rest is chaff.

                Best results to date:

                CO2 mist
                EI
                ADA amazonia soil(no powersand) + mulm.

                I have several tanks to compare the full ADA line against as well as an entire LFS that uses and carries nothing but ADA.

                I am both helping ADA and ripping on them at the same time.
                Same case for Dupla way back when and most things and PMDD etc.

                I do not blindly accept things.
                Nor should you.

                But at least try them to see if they work for the reason's claimed.
                Amano still thinks excess nutrients in the water column cause algae.

                Regards,
                Tom Barr
                www.BarrReport.com

                Comment


                • #9
                  Re: venturi not working properly

                  I've seen what the mist can do but I've had real problems dispersing the mist all over the tank (a Fluval "Lily-pipe" in back-right corner and a venturi loopback reactor beneath it) because of the thick vegetation. The plants near the reactor on the right went nuts, but the left part was a problem.

                  Because the Fluval is old and can't deliver enough current with a spraybar and tight rigid fittings which were hard to move, I adjusted the aquascape instead of the equipment

                  Now I have a triangular layout with the highest point on the left and an open area and the "lily-pipe" on the right managing to mist everything real good.

                  The cool thing about the mist is that folks see the need of good circulation. I bet that with the same setup that disperses the mist evenly throughout the tank you would get great results without the mist also.

                  Comment


                  • #10
                    Re: venturi not working properly

                    who has a venturi and uses a spraybar?
                    I need some examples as to where to place them.

                    I currently the venturi at the back center, near the substrate

                    I have a spraybar that is above the venturi and is spraying vertically down against the venturi

                    there is actually quite a lot of micro bubbles floating around the tank, but I do not know if that is caused by the surface movement.

                    can too much light be the cause as well?
                    I have 2x96W over the 50G.
                    but I have one 96W on for 11 hours. and the other one on for 8hours.

                    I've tried to use only one light. but because my tank is 18" wide. and have quite alot of plants. there isn't enough light in some places and plants will die very quickly (also there is no pearl)

                    Comment


                    • #11
                      Re: venturi not working properly

                      Jade,

                      Maybe a pic will help:



                      Ignore the water spots and the bubbles on the powerhead as the tank was just rescaped today and I didn't plan on posting any pics

                      The reactor is on the far left, the filter intake is in the middle, and the spraybar is mounted vertically on the right. It seems by your description that your spray bar is mounted horizontally across your tank and the flow actually goes from top to bottom. I think you may get better dispersion of the bubbles if you move the spraybar to a vertical position. This still allows some surface movement also.

                      I just moved the venturi reactor today. It was to the right of the spraybar but the mist was not getting blown about the tank very well due to either an underpowered or dirty Eheim Ecco and the plants location. I decided to try moving the reactor to the left of the intake and letting the bubbles get sucked into the intake. I know this isn't in keeping with the mist idea, but the mist wasn't getting the job done as mentioned. Either moving the spray bar or changing the location of the reactor may be worth a try, especially if you can't get the mist blown around the tank with your filter and plant location.
                      Matt

                      South Western Ohio Aquatic Plant Enthusiasts (SWOAPE) member

                      Comment


                      • #12
                        Re: venturi not working properly

                        You might want to consider feeding the CO2 directly into the intake of a small powerhead and output it with a spraybar along the bottom rear back of the tank pointing forward. That should spread the mist out evenly...ymmv.

                        Regards
                        Peter Gwee

                        Comment


                        • #13
                          Re: venturi not working properly

                          Have tried the Rio RVT 600, misting is great-too great. Found a CPVC 1/2" tube will fit over pump outlet- going to try to drill a 42" line, capped at the end (similar to an Eheim discharge line) and hook it up. Misting and pump, for my 75, is a bit too much. Guess a lot of it depends on your personal tastes- I want the misting, but not if it's going to destroy my viewing of the tank. :gw

                          Comment


                          • #14
                            Re: venturi not working properly

                            Hiya all...

                            i would like to chime in here with a question for matpat if i can ....

                            in regards to your vertical spraybar ... other than the fact that it's vertical ... it's just a regular spraybar right ... basicallly a plastic tube, sealed at one end with a row of small holes along it's length so that it sprays out the water ... is that correct?


                            secondly ... the reactor ... i thought that they were empty inside ... yours looks like its got some kind of nmedia inside it ... or is that a cloud of bubbles?

                            thanks and regards
                            aussietanker
                            33 US G (125L) ------ Aqua-One 620 Tall - L: 24" (60cm), W: 14" (36cm), D: 24" (60cm) ; Modified Hood with 2 x GE 55W 21" AquaRays (9325 K) under AH Supply Reflectors; Fluval 304 Canister Filter;Substrate = 2" JBL AquaBasis Plus nutrient ground cover + 2" of 50% mix of Flourite & Onxy Sand ; JBL ProFlora Pressurized CO2 + REXX DIY CO2 Reactor; ViaAqua 150W Glass Heater @ 26C/79F;Fish = 2 x SAE; 2 x Clown Loaches; 15 x Cardinal Tetras; 2 x Orange Angels

                            Comment


                            • #15
                              Re: venturi not working properly

                              Originally posted by jonathan11
                              Have tried the Rio RVT 600, misting is great-too great. Found a CPVC 1/2" tube will fit over pump outlet- going to try to drill a 42" line, capped at the end (similar to an Eheim discharge line) and hook it up. Misting and pump, for my 75, is a bit too much. Guess a lot of it depends on your personal tastes- I want the misting, but not if it's going to destroy my viewing of the tank. :gw
                              I think in cases like this, yes, it can be distracting to a large degree.
                              I will typically blast the outflow along the back wall, slightly into the wall, this cuts down the flow and keeps most of the bubbles in the back, hitting plants.

                              Most of the mist flow patterns do this I've set up.

                              Regards,
                              Tom Barr
                              www.BarrReport.com

                              Comment

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