Aqua Clear self priming?

[Jeff]

I'm 99% of the time a deep sleeper. But last night was different for some reason. I'm in Michigan, and we had a big storm that knocked out the power. The storm woke me, and I saw my alarm clock was out. Fell back to sleep after that.

Woke up a little later, and saw that the power had come back on. I raced downstairs to my 10 gallon tank, and saw that my Aqua Clear 30 was running. Huh....ok - maybe it was a quick power outage...and the filter didn't have time to 'think' about it. Thought nothing of it.

But, then again, the power went out. Woke up again of course, as the storm had gotten louder somehow. This time the power was out for hours. Still out when it was time to get up. 

Eventually the power came back on, after I had left the house. This was a solid 5-6 hours that the power was out. I came back to my tank, and my filter was running AGAIN.

Now, I know Aqua Clears aren't self priming....but this was definitely strange.

Anyone else have something similar happen to an Aqua Clear HOB?

[Widgets]

To me, a self priming HOB means it will start working from a dry start. Unless the HOB is draining back into your tank, it should just restart when power comes back on.

My Aqua Clear 110 has only lost it's prime when I do a large water change and it both drains back into the tank and exposes the seam on the lift tube (letting air into the lift tube). It has always restarted after a power outage, and after most water changes.

I have heard reports from others who have lost prime during a power outage. I think a big factor is the "normal" water level in the tank and how much water is pulled back into the tank when power is off. I have my tanks filled to just above the bottom of the trim to reduce the splash from the HOB.

[Jeff]

I guess my question relates to filters such as the Tidal series.

One of the biggest things you hear is - "it's self-priming...in case of a power outage, you don't have to fill the filter up with water when the power comes back on - it'll restart on it's own due to having the motor in the aquarium."

If this really is the case with Aqua Clears, where I don't have to worry about it during a power outage...then, shouldn't that theoretically negate a self-priming aspect of a different filter?

[Widgets]

I have never had a HOB filter that would loose prime when it lost power. I hear reports of filters loosing prime. The only way I can see this happening is for the tank water level to be sufficiently lower than the filter water level, such that when the water levels equalize there is not enough water in the filter. I only have this happen when I do a large water change. When this happens, it is quick and noticeable with the gurgling sound as it sucks in air.

You said that you have lost power multiple times without your filter loosing prime. This should give you comfort in knowing that your filter when used on a tank with your water level does not have have a problem loosing prime. 

[Jeff]

Then why are some people so big on self-priming hob filters then?

Is it just false advertising? Not in the way that the filter won't self prime....but in the way that others DON'T lose their prime...

[Widgets]

My filter does loose prime when I do a large water change and the tank water level drops too low, requiring me to add water to the filter to restart. A self priming filter would allow me to skip that step.

I have heard of complaints about the noise of the HOB water returning to the tank. To me this is describing the waterfall that happens when the tank water level is too low. A low enough water level will cause the filter to loose prime. You can fix the problem by maintaining a higher water level in the tank, or by switching to a filter that is self priming.

Note that in my opinion there is nothing magic about the self priming filter. The pump motor and impeller are placed in the tank instead of in the filter. They push water up the intake tube instead of sucking the water up the intake tube. There are some advantages of sound dampening and cooling provided by having the pump in the tank. A disadvantage is more tank space taken up by the pump housing.

[Guppysnail]

With all my Aqua clears as long as water level has not been drained they come back on unless the impeller is dirty which happens in days from cleaning. So self priming no they I’ll not suck water up enough to operate if they drain but self starting yes if really clean impellers. I have learned to use a pen tip to budge the impeller when it’s dirty and not contacting enough to start spinning and it starts whirring. That trick is crazy helpful in the middle of the night when I don’t want to fuss with it if the power goes out. 

[Jeff]

On 3/6/2022 at 8:56 PM, Widgets said:

Note that in my opinion there is nothing magic about the self priming filter. The pump motor and impeller are placed in the tank instead of in the filter. They push water up the intake tube instead of sucking the water up the intake tube. There are some advantages of sound dampening and cooling provided by having the pump in the tank. A disadvantage is more tank space taken up by the pump housing.

This has been my thing all along. Not a fan of more equipment in my tank. Glad someone else agrees with me - the 'self priming' is not an advantage for a filter. 

 

On 3/7/2022 at 9:18 AM, Guppysnail said:

With all my Aqua clears as long as water level has not been drained they come back on unless the impeller is dirty which happens in days from cleaning.

I clean my filter and impeller every week when I do water changes. So, this has never been an issue with me either. 

Preventative maintenance is such a huge underrated thing you can do, to help keep your aquarium running smoothly. Just one less thing to have to worry about.

[Jeff]

Another example of Aqua Clear filters self priming. 

My power was was out for the last 24 hours, and my Aqua Clear came back on when the power did. 

Edited August 26 by Jeff

[nabokovfan87]

On 3/6/2022 at 5:35 PM, Jeff said:

Then why are some people so big on self-priming hob filters then?

Is it just false advertising? Not in the way that the filter won't self prime....but in the way that others DON'T lose their prime...

There's multiple ways to look at it, but understand that each install of the aquaclear is different.

Some will start up just fine. Others will start, but the impeller doesn't actually spin until you start it manually with a chopstick or your finger. And other times it just won't start and will not pull water in.

There's a variety of reasons for this.

The tidal (and other filters of similar design) push water from the tank into the HoB container. Aquaclear and older filters pull water from the take through the lift tube.

[JChristophersAdventures]

Based on the discussion, so far, I think it might be helpful to differentiate between self priming at install/initial start-up and when its been up and running with a power interruption. On the initial install, the filter is primed by manually pouring enough water into it to submerge the pump system. I had one back in the day (and they haven't really that changed much) and then it was impossible for a dry AC filter to start up on its own.

After it has been running, it is hit and miss. As some have noted, during shorter outages, the pump is likely to successfully start up again as it is still primed with the water remaining in it. However, it is not uncommon for it to lose enough water from the pump chamber over time that it is closer to the "out-of-the-box" condition... too dry or not enough water to start.

I believe the big variation people experience as to what happens to them, in a power outage, is also largely a matter of the condition of the impeller chamber at the time. If the chamber is a little gunky, or the impeller worn, there is probably a higher chance that the pump won't function again without some intervention. Both the Tidal and AC filters a not tightly engineered designs... they leak throughout the design... they leak below the water line, but nobody cares because the aquarium catches those leaks... the above water line leaks are captured by the outer shell of the filter and eventually directed back into the tank over the water fall.

Compare that to a fluid pump (either one in or out of the water) with tubing attached to either end... nothing leaks out because they are engineered to be sealed tight against that happening. The only reason the Tidals are always self-priming is that the pump is in the water, so the water can't leak away creating an air void around the impeller causing it to "suck wind" instead of water. This is also why when the water level falls below a certain level, the Tidal also has this same problem as the AC and makes all kinds of unpleasant noises due to the increasing air around the impeller.

If highly modified, it can be argued that the Tidal is the best filter, but out-of-the-box, I would definitely give the nod to the AquaClear. Thanks.

[Guppysnail]

@JChristophersAdventuresOne filter not mentioned often is the Marineland penguin biowheel. Though I don’t use the biowheel itself because I use my hobs as planters and the plants stop the wheel I really like the filter. 
After a water change mine start right up even though not self priming. During water change my aquaclears drain to far so I have to pour water in. 
The media compartment is huge. I stuff that with sponge. 
The outflow rocks! Instead of nearly dropping water straight into the tank it has a flat lip at the end. It pushes water across the surface in a ripple pattern oxygenating the water and dispersing it and sweeping the debris from the floor. 
All around a great filter.  In almost 2 years I’ve not had an impeller stop just because it was a bit dirty or for any reason like the aqua clear.  Much less fussy filter. The plastic is sturdier since it has some give to it. I definitely feel more bang for the buck though less fancy a better value per dollar. 
 

To add you don’t need all the modifications you do on a tidal to keep it from sucking critters up. Just a prefilter sponge and it’s fry/ shrimp/ snail safe. 

[Galabar]

Self-priming does not mean that the filter restarts after a power outage.  All filters will be designed to restart after a power outage.  If your filters restarts after a power outage (which it should), that doesn't mean it is self-priming.

As others have mentioned, self-priming means that the filter will fill itself with water, starting from empty.  An Aqua Clear or other non-self-priming will need to have water added to it in order for it to start.

Also, given that self-priming filters have the pump in the tank, it will more or less guarantee a restart after a power outage.  With Aqua Clear and other non-self-priming filters, they will usually restart after a power outage but sometimes not (both experiences have been shared here).

So, the benefits of self-priming are (a) no need to fill the filter to get things started, and (b) a guarantee that the filter will restart after a power outage.  The disadvantage is more bulk in the tank as well as an additional electrical cable in the tank.

 

Edited August 27 by Galabar

[nabokovfan87]

On 8/26/2023 at 7:40 AM, JChristophersAdventures said:

I believe the big variation people experience as to what happens to them, in a power outage, is also largely a matter of the condition of the impeller chamber at the time. If the chamber is a little gunky, or the impeller worn, there is probably a higher chance that the pump won't function again without some intervention. Both the Tidal and AC filters a not tightly engineered designs... they leak throughout the design... they leak below the water line, but nobody cares because the aquarium catches those leaks... the above water line leaks are captured by the outer shell of the filter and eventually directed back into the tank over the water fall.

To expand on the "condition of the impeller chamber" as a cause for concern....

A lot of the issues with the AC restarting, noise, etc. can be attributed to the impeller shaft being damaged.  It doesn't take a lot of time for that impeller shaft to show some wear either.  To be clear, I am not trying to "hate on" the AC filter.  People enjoy them and admire them, more power to you, but there is also a lot of great information that has been gathered for decades at this point with user feedback. 

Common reasons any filter without self-priming may not start:
1.  Poor maintenance
2.  Impeller is past service life or damaged (magnet is weak)
3.  Sand substrate
4.  Intake is not aligned
5.  Air is trapped, pump is not strong enough to push the air through the pump.
6.  Filter is leaning "backwards" and drained itself during power outtage
7.  Water siphoned down the intake and out of the box
8.  Water level in the tank is low (this is not the same as #6 or #7)
9.  Pump is on, impeller is stuck (usually because of #1-3)
10. Surface of the pump shaft / impeller is worn down and no lubrication was used during maintenance

I am sure there's other reasons, but you get the just.  There's so many reasons for a filter to just not start up.  This doesn't mean that X is better than Y or that because one person had a filter start up that they all do (or don't).  Unfortunately there are defects, manufacturing flaws, shipping damages, and other reasons for things to just not last as long as they should also!

In my experience, the #1 reason an AC won't start back up.... this thing:
(first one is a very extreme example, the others are more typical)
 

On 8/26/2023 at 8:12 AM, Guppysnail said:

The outflow rocks! Instead of nearly dropping water straight into the tank it has a flat lip at the end. It pushes water across the surface in a ripple pattern oxygenating the water and dispersing it and sweeping the debris from the floor. 

I wish I had a cross-section of every HoB on the market for this.  Definitely something I pay attention to!