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View Full Version : Does anyone make a powerhead that DOES NOT blow bubbles?



MikefromNH
01-25-2005, 8:33 PM
I have an AC 301 and an AC 50 (new 401) and both impellers cavitate:mad:. The 50, which I'm currently using, is the worst of the two, blowing poofs of bubbles every 15 seconds or so. It is totally submerged and nowhere near any source of bubbles. It doesn't really make the tank look bad but I feel, due to the cavitation, it's pulling dissolved oxygen out of the water and sending it to the surface as large bubbles. My fish seem fine but I still don't like the idea. I have $70 invested in these pieces of junk!:mad2

Does anyone have any recommendations on non-cavitating powerheads? I'm using it for circulation and looking for around 250 gph flow rate. I also have a quick filter on there for a little extra water polishing.

BTW, I tried both units without the quick filter with the same results. I also tried adjusting the flow rates to no avail.

QCppg
01-29-2005, 2:04 AM
I have that same powerhead, and an old version of the 801 (I think it is anyways, it looks identical). Neither cavitates in FW or SW in my experiance.

blitzen25bm
01-29-2005, 2:34 AM
supposedly not the best powerhead but my rio dosent blow any bubbles

RTR
01-29-2005, 8:39 AM
I've never had any AC powerheads cavitate either, unless I restrict the intake. Are you?

MikefromNH
01-29-2005, 2:04 PM
I've never had any AC powerheads cavitate either, unless I restrict the intake. Are you?

At first I thought it was the restriction caused by the quick filter causing the cavitation. After removing it there was no difference. Running it with the flow lever at max actually makes it worse! To me, that dosen't make sense. I don't think this is an isolated problem either.


This is from the FAQ on the Hagen website.

Stopping Air insertion from Power Head Venturi


Problem:In my marine aquarium I'm using Hagen Power Head 402 with a Aqua Clear Quick Filter. But the quick filter is just an additional help in removing some wastes. The main reason why I bought the Power Head 402 was to use it as a wave maker. But I don't want the power head to let out the air bubbles into the water. But that happens even if the air hose is fully closed. Why is that? How can I make a water move without these very small water bubbles?

You must ensure the Power Head cannot get air in to the Venturi and that the impeller is never above the water line.

1) Place the unit fully under the water so no air contacts the unit.

2) Take the air line that came with it, tie it in a knot to close it completely. Then isert the closed tube into the Power Head's Venturi hole. There is an additional hole as well, so the warning to keep the unit fully submersed is very important to eliminate air insertion.

Alternately take a small piece of the airline and squirt a bit of silicon to block it, but leave about a 1/4" of the end without any filling to make it easier to place the airline into the Venturi. If it is completely plugged, the line may not compress enough to allow easy entry into the Venturi hole.

Finally, you might find that submersing it entirely will eliminate all air bubbles anyway, without knots or plugs, the really important point is that the output must be below the surface enough that it cannot draw air into the system to blow it out. Simple submersion often cures this.

Thanks for your answer on the air bubbles problem. The problem is that even with the whole unit placed fully under the water and fully closed air line, the air bubbles still are blowing into the water. Those are very small bubbles. Much smaller then they normally occur when the air line stays open. I was thinking if is possible that impeller by its fast rotation makes the bubbles itself?

It is always a possibility, but to continually create air bubbles, the air must be coming from somewhere. That is why I suggest that you ensure the entire unit is placed under the water, if the air is entering the system from the input, it should slowly eliminate the problem as the bubbles break at the surface and have no way to be replaced. You might want to shut off the system for a few minutes to allow any air in the water to rise unhindered and break at the surface. Another possible place where air is entering is where the water is boiling at the surface. Although this is pretty desirable, it may mean you must move the powerhead away from the filter agitation source to allow the bubbles entering to break at the surface rather than get trapped by the PH input.

As far as the Powerhead actually manufacturing air under water, that is really not one of the traits I have ever encountered in a powerhead. Air production in a properly installed PH is not a factor. The system does not cavitate to chop up and create bubbles in normal operation. That is why I feel you must find the original source of the air being input into the Power Head. I have always seen that when no air enters the input, and no air is allowed through the Venturi and starter holes, then no air can be output. Hope that helps a bit, look for a source of air, Power Heads really are not able to spontaneously generate bubbles to the best of my knowledge.
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Since I'm only using the powerhead for circulation I never put the airline on there to begin with. I figured if it's submerged what would it matter if there was a knotted airline on there. Maybe that's the problem though I can't see how it could be. Also, I removed the impellers and looked for any imperfections on the blades. There were a few tiny casting flaws that I cleaned up with an exacto knife but the problem is still there.

QCppg
01-30-2005, 3:58 AM
Because of the way an impellar works it is doubtful that you are getting cavitation unless you have an ENORMOUS quantity of dissolved gas. Cavitation takes place in the low pressure zone behind a propellar blade at high RPMs. An impellar flings water rather than pushing it, and few household AC motors turn faster than 3,600 RPM, which is normally too slow for cavitation.

daveedka
01-30-2005, 8:58 AM
I have never seen these bubbles with my penguin powerheads, but recently I bought a smaller aquarium systems powerhead, and do get occasional bubbles. I attributed it solely to pearling from the plants, but your post makes me curious. Either way with the plants, my tanks usually looks like a glass of soda so the bubbles aren't a big deal for me. You might try penguin, but I imagine the source of the bubbles will be the same for any powerhead, and therefore you won't see a difference.
dave

pl*co
01-30-2005, 9:10 AM
My Penguin 1140 (300 GPH) Power Head does not blow bubbles unless I adjust the airline to do so. Otherwise, it creates a nice current in the tank. It's pretty quiet too.

Would you like to have it? No charge. I never use it because my tanks aren't large enough for that much power. I bought it back when I was a newbie and didn't know any better. :( I recently tried it out (just to see) in a 30 gallon that I recently acquired and it knocked over a fully grown Convict when it swam too close. :p Would you believe I actually bought it for a 10 gallon originally? :laugh:

MikefromNH
01-30-2005, 3:34 PM
My Penguin 1140 (300 GPH) Power Head does not blow bubbles unless I adjust the airline to do so. Otherwise, it creates a nice current in the tank. It's pretty quiet too.

Would you like to have it? No charge. I never use it because my tanks aren't large enough for that much power. I bought it back when I was a newbie and didn't know any better. :( I recently tried it out (just to see) in a 30 gallon that I recently acquired and it knocked over a fully grown Convict when it swam too close. :p Would you believe I actually bought it for a 10 gallon originally? :laugh:

Thanks, I may take you up on your offer. First, I'm going to contact Hagen to see what they say. Like a moron, I threw away the receipt from petsmart so I cant return it ($50 in the store!:mad: ). Hopefully Hagen will warranty/replace it or something. Does your Penguin accept any sort of quick filter?

pl*co
01-30-2005, 3:50 PM
Hi Mike... what is a quick filter? I suppose if I have to ask, it means no it does not. :) Do you mean like this? Mine has a cone shaped thingy on the end of the powerhead like in the picture at the url below. I will post a pic in a minute and maybe you can tell. I doubt it though. I will also check the booklet. Be right back.

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=4638&ref=3167&subref=AC&N=2004+22768

MikefromNH
01-30-2005, 4:03 PM
Hi Mike... what is a quick filter? I suppose if I have to ask, it means no it does not. :) Do you mean like this? Mine has a cone shaped thingy on the end of the powerhead like in the picture at the url below. I will post a pic in a minute and maybe you can tell. I doubt it though. I will also check the booklet. Be right back.

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=4638&ref=3167&subref=AC&N=2004+22768

It is exactly the thing under the cone shaped strainer. It offers a bit of filtration in addition to the circulation properties of the powerhead.

Also, according to the link, Aqua Clear claims "the quick filter fits just about any powerhead". I assume they mean other brands, not just the models they offer. I just e-mailed Hagen about the bubbles. I'm going to try and get their # so I can talk to someone directly. Thanks for your effort, pl*co!

pl*co
01-30-2005, 4:11 PM
Ok, I checked the booklet and looked it up on the Internet too. No mention of a quick filter, but now that I look closer, I see how it might fit. The cone shape strainer is what makes the quickfilter adaptable. Here is a web page with a pic and info. Let me know if things don't work out with Hagan.

http://www.thatpetplace.com/Products/KW/F68/Class/Fish+Supplies+Power+Heads/T1/F68+0221+0177/EDP/11515/Itemdy00.aspx

MikefromNH
01-30-2005, 8:14 PM
Ok, I checked the booklet and looked it up on the Internet too. No mention of a quick filter, but now that I look closer, I see how it might fit. The cone shape strainer is what makes the quickfilter adaptable. Here is a web page with a pic and info. Let me know if things don't work out with Hagan.

http://www.thatpetplace.com/Products/KW/F68/Class/Fish+Supplies+Power+Heads/T1/F68+0221+0177/EDP/11515/Itemdy00.aspx

I see what you mean in the pic, it definately looks like it would work. I'll get back to you when I find out what's up from Hagen. Thanks again.

slipknottin
01-30-2005, 8:46 PM
ive had issues with powerheads doing that, I cut off the grill on the bottom, and replace it with a longer tube type strainer. Usually solves the problem.

MikefromNH
01-30-2005, 10:16 PM
ive had issues with powerheads doing that, I cut off the grill on the bottom, and replace it with a longer tube type strainer. Usually solves the problem.

Glad, I think, to see I'm not the only one with this problem. I did remove the grill on the bottom. I also removed the 2 grills inside the quick filter. Still bubblin'.

So far no one seems to think it's cavitation. Like I said it's totally submerged and nowhere near any bubbles. The weirdest thing is both my 301 and the 50 do this. How could my water be overly saturated with oxygen? I have an xp-3 with the power nozzle (minimal surface agitation, maximum current) on the output. Also, I have a 4" or 6" (can't remember) airstone behind my driftwood. I doubt the airstone is causing the oversaturation. :confused:

pl*co
01-31-2005, 12:18 AM
You know, I read your original post again and now I'm wondering if the fssst, fssst, sound is what you are referring to. I have heard that and in the time sequence you stated. The way I got that to stop was to adjust the diffuser in a more upward position. That is, slightly up from where the instructions say is the correct position. The air valve was off as well... or I can cap the Venturi.

MikefromNH
01-31-2005, 8:59 AM
Unfortunately, my AC50 does not have a diffuser, nor is there one available. Pretty stupid if you ask me. I tried the diffuser from the 301 but the output tube diameters are different. If I end up keeping it I'll have to DIY something.

You said you heard the noise. Did you also have blasts of bubbles?

slipknottin
01-31-2005, 9:40 AM
How long have you been running it submerged? Sometimes powerheads will fill with air and slowly release the bubbles back into the tank. Try running it upside down for a little while.

MikefromNH
01-31-2005, 10:58 AM
I've had it (AC50) for 4-6 weeks. It started as soon as I plugged it in. It's been submerged the entire time. Each time I've taken it out to clean the filter it always blew extra bubbles, but thats to be expected. After that, every 15 seconds.

Maybe it's trying to tell me something.