Need some input on flow rate & design (plus a micro bubble problem) please!

[cryptrix]

I currently have a 25g IM Lagoon AIO tank, which I've been trying to get set up properly regarding both the flow design, flow rate, and an annoying issue with microbubbles which is probably related to getting my flow correct, and I could use some input. I have some fish/inverts and live rock, no corals yet, but will be starting with softies -> LPS once I get my params correct

So the 25 Lagoon has two built in return nozzles on the back wall facing forward, and comes with two 130 gph pumps, one for each return. One of these pumps arrived DOA, so I just replaced both with two Sycce Syncra 1.0 (250 gph pumps), figuring I'd end up wanting more turnover regardless (On max that gives me a 20x turnover if I understand?). In addition, I have also recently added a Jebao SOW-4 wave-maker, which I have placed in the middle below and between the two returns.

For a while I did not seem to notice any issues, but at some point in tweaking things I started having problems with micro bubbles, and now no matter what I do, when I have both return pumps running, one of them always spits a bunch of bubbles every few seconds. I have tried reducing both pumps to the lowest rate they have, both to max rate they have, swapping nozzles, swapping tubes, running with/without filter socks, and with/without matrix. Then I thought maybe I had the water level too high, and played with that in the full range of my return section water height, still bubbles.

What else should I be considering.. is 500 gph simply too much flow for this tank, pumps too large? Is something wrong with the way my filter sock sort of overflows? What else can I do to test things? I tried to attach some pics of the placement and water height of rear sections.. Also would take any input on my placement of the wave-maker in relation to the returns, as well as directing the return nozzels (they have some slow directional adjustment not a ton). Thanks!


TL;DR - Can't figure out why I have microbubbles, while also trying to get a good flow design. Help

 

[TX_REEF]

if you are getting micro bubbles, that means something is sucking air somewhere. I would ensure there are no even slightly loose connections on any of the plumbing fittings that come in contact with air. Also, it looks like you have a significant drop from your overflow into the filter chamber, which would cause large bubbles, which would be chopped into microbubbles by the return pumps and pumped into the display.

Aside from that, perhaps also consider swapping your fan return nozzles for random flow nozzles, this is a good way for you to get more randomized flow using the return pumps you already have in place. Something like this: https://amzn.to/3ZR57bd would even allow you to have 4 separate outlets from your 2 returns.

 

[cryptrix]

if you are getting micro bubbles, that means something is sucking air somewhere. I would ensure there are no even slightly loose connections on any of the plumbing fittings that come in contact with air. Also, it looks like you have a significant drop from your overflow into the filter chamber, which would cause large bubbles, which would be chopped into microbubbles by the return pumps and pumped into the display.

Aside from that, perhaps also consider swapping your fan return nozzles for random flow nozzles, this is a good way for you to get more randomized flow using the return pumps you already have in place. Something like this: https://amzn.to/3ZR57bd would even allow you to have 4 separate outlets from your 2 returns.

@TX_REEF Thanks for the input. So I actually already have similar split nozzles for the four smaller outputs, I'd just put the stock ones back temporarily to play with the configuration, mine just are not random flow. I think I would prefer to have a consistent output from the returns, and keep the random flow generation from the Jebao, its hard to imagine I cannot get the correct solution with these components. Maybe worth mentioning I also have a slightly larger hygger 2100gph wavemaker, but that was way too much even on the lowest setting

I've filled so the pump chamber drop is now ~1" rather than several as noted, for now the microbubbles are still every few seconds at an even higher rate. What would you say the ideal levels are for the rear chambers here with this configuration?

I'll check the hoses again and be a bit more meticulous, and add additional seal/sealant. I sure hope that is the problem because I'm out of ideas and its driving me nuts.. Aren't I supposed to be aiming for a higher (20x) turnover anyway? Currently my pumps are at like 20% each so I'm probably getting 3-5x turnover.

 

[TX_REEF]

@TX_REEF Thanks for the input. So I actually already have similar split nozzles for the four smaller outputs, I'd just put the stock ones back temporarily to play with the configuration, mine just are not random flow. I think I would prefer to have a consistent output from the returns, and keep the random flow generation from the Jebao, its hard to imagine I cannot get the correct solution with these components. Maybe worth mentioning I also have a slightly larger hygger 2100gph wavemaker, but that was way too much even on the lowest setting

I've filled so the pump chamber drop is now ~1" rather than several as noted, for now the microbubbles are still every few seconds at an even higher rate. What would you say the ideal levels are for the rear chambers here with this configuration?

I'll check the hoses again and be a bit more meticulous, and add additional seal/sealant. I sure hope that is the problem because I'm out of ideas and its driving me nuts.. Aren't I supposed to be aiming for a higher (20x) turnover anyway? Currently my pumps are at like 20% each so I'm probably getting 3-5x turnover.

I personally would not want any drop from the overflow into the filter, I'd want the water level to be slightly above the bottom of the "teeth". If that doesn't solve it (give it some time in case old bubbles need to be dislodged) then it's almost a certainty that the microbubbles are from air intrusion in above-waterline plumbing. I also assume you don't have a protein skimmer? that could be another culprit.

On the random flow nozzles, that wasn't a suggestion to fix the bubbles, just a generalized idea

 

[cryptrix]

Hmm thanks. Question though, for this AIO design, I was under the impression I basically have no control over the water levels in the display, overflow chamber 1 (filter sock), and overflow chamber 2 (empty), so pretty much only the pump section? I tossed in a pic of the overflow design in case you aren't familiar with this exact model.

Anyway, I raised the water until the bubbles were significantly reduced, which they are for now.. but my water level seems very high?.. its about 1/2-1" above the lowered edge between chamber 2 and the return pump middle section, so no drop off (don't I want a drop off for gas exchange?).

I also don't know if water is supposed to be slightly running over the top of the filter sock like it is, letting some debris through, although that happens at any water level. Almost like its not porous enough but its set up exactly how IM suggests (and its the sock that came with the tank).