# Aquatop HOB w/ UV?



## DarkCobra (Jun 22, 2004)

Wondering if anyone has used one of these, like this one:

http://www.truaqua.com/aquatop-power-filter-pf-uv-25.html

Would like to have an easily movable UV sterilizer for occasional use on any of my six tanks, rather than regular use. This seems ideal, as it takes up no space in the tank. And could potentially be safer than fully submerged alternatives.

But I can't find any reviews on it at all. And I don't know if it will fit over the rim on my 46G bowfront.


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## NJAquaBarren (Sep 16, 2009)

Flow rate is a little low for a 46g. Water needs to be exposed to the UV for it to do anything and at 90gph flow exposure may never be adequate.

Also, 7 watts isn't very strong. Some of the larger nasties won't be killed by it. 

So, I'd say save up for a better solution. There are dedicated UV products that come with the accessories to be configured for HOB. Just attach a pump and go. Search the web stores for more info. Some of the sites have write ups on the effectiveness of UV of various strengths.


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## DarkCobra (Jun 22, 2004)

NJAquaBarren said:


> Some of the sites have write ups on the effectiveness of UV of various strengths.


Just spent 20 minutes looking at many of them, and the recommendations are all over the place.

My other tanks are 5, 10, 20, 25, and 29, as well as the mentioned 46G. I don't need or expect rapid, 100% sterilization on all of them from a single unit; just something that physically fits, can be easily moved, and works to some useful degree on all.

From looking at reviews, it seems that most UV sterilizers aren't very reliable until you get into the $200-and-up range. Not willing to pay that much at this time for something I'll only use occasionally, and without some prior personal experience with UV (excluding my attempt at DIY UV).

So I'm just trying to find out if _this particular unit_ isn't significantly worse than other options, in a similar range of price and utility. If you have a specific alternative that meets these criteria (other than the disposable-by-design Green Killing Machine), I'd be interested.


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## zdnet (Aug 13, 2010)

To prevent UV light from harming our eyes, all the UV sterilizers that I am aware of have an opaque container to prevent direct eye contact with the operating UV bulb. The PFUV filter does not have such opaque container. I wonder whether that will negatively affect the eyes of the fish or even that of the person starring into the tank.

As to the UV strength, I have used a variety of merely 5W UV sterilizers and have no problem with their effectiveness.

As to using an UV sterilizer in a small tank like a 5-gallon, the heat generated by just a 5W UV bulb can quickly raise the water temperature by several degrees. Higher wattage bulb will generate more heat.


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## DarkCobra (Jun 22, 2004)

UV-C is blocked by most plastics. That's why they use more expensive and fragile quartz sleeves around the bulb. So that's not a problem.

But I didn't even think to consider heating. Good point, thanks!


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## NWA-Planted (Aug 27, 2011)

I have a couple products from aquatop, one of them being a canister filter with the uv, I have not had any issues, appears to work fine, water temperature has never climbed either.


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## DarkCobra (Jun 22, 2004)

I went ahead and purchased an Aquatop PFUV-25. Which goes by other names as well.

Remember that I just want an entry-level "emergency" UV on hand, that will easily transfer to any of my tanks without taking up room _in_ the tank; and provide at least some effectiveness in the largest 46G. I do not require a high-power or high-reliability unit that can be expected to hold up with regular use. At $40, this unit seemed like it might fit my needs.

Here's my initial review.

The outer housing and intake parts are made of brittle plastic. An impact will probably shatter them. The intake parts already show some stress cracking, after only assembling them. Still, they should hold up a long time, as long as they're treated gently and no accidents occur. This wasn't unexpected for the price, but it would have been a pleasant surprise if it were more durable.

The media capacity is tiny. In terms of biological filtration, this would be a poor substitute for a regular HOB, even the el-cheapo ones at Walmart. It's really only useful for UV treatment, and additional flow or surface agitation. I didn't even bother to install the media.

The UV lamp is on a separate plug. The electronics are in a "brick" style power supply, with a power switch, and a replaceable inline safety fuse. All nice features.

It doesn't fit properly over the rim on my 46G. It does at least fit _improperly_, hanging at a bit of an angle. The instruction manual says it won't fit on aquariums with a rim of more than 3/4", and mine is 1"; would have been nice if that was mentioned more prominently in the product description.

The intake tube tube has some niceties. First, a 0%-100% flow adjustment, which lets you reduce flow rate. Since slower flow improves UV effectiveness on the treated water, this could be useful for treating tougher parasites, at the expense of GPH treated.

Second, a simple check valve. Should the water level drop too much, water cannot siphon out of the housing; presumably needed to prevent the UV from running dry and overheating.

Finally, a surface skimmer, which because the HOB was riding high and at an angle on my 46G rim, wouldn't work. Probably not something I'll ever use anyway.

With the flow adjustment at 100%, there was bypass. Water was spilling over the top of the impeller chamber back into the tank, without passing through the media/UV chamber. Holding the HOB at the level angle it would normally be actually makes it _worse_. At max flow and normal orientation, I estimate the GPH treated to be 25% less than the GPH flow due to the bypass.

It looks different than in the pictures, which depict a smoked plastic housing with a diffuse blue glow from the UV. The outer housing is clear, and the UV assembly is completely opaque; revealing no glow. The only way I could tell the UV was operating was by looking through the housing for a tiny dot of blue light shimmering in the water's surface over the UV. While the outer housing is clear, it presumably still blocks UV, as the lid contains a big warning sticker not to run the UV without the lid installed.

Apart from verifying the UV was operating, I have no way of telling how well it works at this time; since I currently have no tanks requiring treatment or with visible haze. It will probably work as well as any other cheap UV; with the effectiveness naturally dependent on both flow rate and tank size.

I got what I paid for. This is in all respects a $40 unit, not some miracle of cheap labor and manufacturing. But it appears to meet my limited expectations for an easily movable emergency UV unit.

As a quick side review, I also purchased an Aquatop CP-12 circulating pump for $24, which is a 1,321GPH Koralia clone. This I am impressed with! More durable construction, excellent flow, low noise, both magnetic and suction mounts are secure. If it lasts, this is a great value.


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## zdnet (Aug 13, 2010)

DarkCobra said:


> Finally, a surface skimmer, which because the HOB was riding high and at an angle on my 46G rim, wouldn't work.


A surface skimmer works by sucking in the surface water and then breaking the surface film. But the Aquatop filter sucks in water from an intake deep in a tank. I wonder how it managed to suck in the surface water.




DarkCobra said:


> It looks different than in the pictures, which depict a smoked plastic housing with a diffuse blue glow from the UV. The outer housing is clear, and the UV assembly is completely opaque; revealing no glow. The only way I could tell the UV was operating was by looking through the housing for a tiny dot of blue light shimmering in the water's surface over the UV.


With the UV assembly completely opaque, that means water has to get into the assembly in order for the UV light to do its work. I wonder how the water flow inside the assembly is managed to ensure that the water is properly exposed to the UV light. May be you can show us a photo of the assembly?




DarkCobra said:


> While the outer housing is clear, it presumably still blocks UV, as the lid contains a big warning sticker not to run the UV without the lid installed.


Not sure I understand that. When the UV assembly is completely opaque, it blocks all light. So, why was the warning?


Thank you for the very interesting review.


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## DarkCobra (Jun 22, 2004)

zdnet said:


> A surface skimmer works by sucking in the surface water and then breaking the surface film. But the Aquatop filter sucks in water from an intake deep in a tank. I wonder how it managed to suck in the surface water.


It's an optional part you can install as a segment of the intake tube. Floats to match the surface of the water, sucking a bit from there; and the rest from the deep intake.



zdnet said:


> With the UV assembly completely opaque, that means water has to get into the assembly in order for the UV light to do its work. I wonder how the water flow inside the assembly is managed to ensure that the water is properly exposed to the UV light. May be you can show us a photo of the assembly?


I don't want to fully disassemble it. If the gaskets or quartz sleeve are as cheap as the rest, I would be taking a chance in doing so; and if I leave it alone this should last many years given the intended occasional use.

I was able to figure out how it works by peering through a gap at various angles. Can't fully show that with a photo, but with an accompanying description it should suffice:










It's a three chamber system. Water comes up through the intake, into the impeller chamber on the left, and goes around the back to enter the media chamber on the top right. You can see the grooves where the media cartridge I didn't install should go.

The UV chamber is the large black object, and the bulb is mounted vertically. See the ring around the UV chamber? When water reaches the top of the media chamber, it enters the UV chamber through that ring.

The UV chamber has a partition inside. So water has to flow all the way down one side, and back up the other side to reach the outflow. Probably has nothing on the efficiency of a Turbo Twist, but at least water is passing the full length of the bulb twice.



zdnet said:


> Not sure I understand that. When the UV assembly is completely opaque, it blocks all light. So, why was the warning?


Easy given the above description. A little escapes straight up through intake/output of the chamber. The lid does block the UV, I checked with a piece of UV reactive material. But does pass some harmless visible light, so at least you some way to tell it's working.



zdnet said:


> Thank you for the very interesting review.


You're welcome! I haven't tried it on my 5G yet. It probably will raise the temp on that small a tank as you predicted, but since I typically have a heater in that tank for QT treatments or fast guppy fry growout, up to 6°F won't be a problem.


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## zdnet (Aug 13, 2010)

DarkCobra said:


> I was able to figure out how it works by peering through a gap at various angles. Can't fully show that with a photo, but with an accompanying description it should suffice:


Very good take! roud: Now I can see how it works.




DarkCobra said:


> Probably has nothing on the efficiency of a Turbo Twist, but at least water is passing the full length of the bulb twice.


One way to assess its UV effectiveness is having a volume of water with some fish food. As the food decompose, water will become hazy with bacteria. Then activate the UV to see how long it will take to clear up the water.


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## JessDay06 (Nov 6, 2011)

I just bought the version of this filter without the UV. I will let you guys know how the surface skimmer does.


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## livingword26 (Oct 28, 2010)

I've been looking at this unit lately. Any further evaluations? All still working good?


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## Jimmyblues (Dec 16, 2010)

DarkCobra said:


> Wondering if anyone has used one of these, like this one:
> 
> http://www.truaqua.com/aquatop-power-filter-pf-uv-25.html
> 
> ...


 


Review on AquaTop PF-UV25

I just bought an AquaTop PF-UV25 for my 20 gallon planted tank and I like it. 

As for fitting your 46 gallon tank, you should go with the PF-UV40, since this filter is rated a lot closer to your tank's size. The PF-UV25 also has very little clearance - it just fits my Aqueon 20 long, so even a fraction of an increase in the width of the lip of an aquarium would preclude your ability to use this filter. Check with AquaTop to see if the PF-UV40 has more clearance.

As for the build quality of the PF-UV40, it is fairly well constructed, and has a heavy duty separate power supply for the UV bulb, which also contains an on and off switch.

I like the flexibility here, since you can run the uv bulb independently of the filter, increasing the life of the bulb.

The 7 watt bulb for the PF-UV25 is also discounted at the TrueAqua Website - $11.95 each. This is a lot better than spending nearly $30 for a replacement bulb for my 3 watt Green Killing Machine Mini.

The management at AquaTop have studied their competitors quite well, and designed a product in their line of UV hob filters that is already attracting lots of positive attention.

In this author's opinion, these uv hob filters are going to force companies such as Aquaclear, Whisper and Fluval to design uv hob filters of their own in the future, if they want to remain competitive. This is especially true given the increased popularity of high tech lighting systems and CO2 injection, which have made it necessary incorporate uv sterilization into aquariums used with these high output lighting systems.

I have several canister filters, as well as a number of Aquaclear hob filters, all of which work well in tanks without CO2 injection.

However, once you add pressurized CO2 with fertilizer supplementation and T5 lighting, it becomes much tougher to keep your water table clear, because of all of the additional nutrients in the water.

The end result is bacterial and algae blooms that make keeping your aquarium's water clear, almost impossible without uv sterilization.

As for the AquaTop PF-UV25, since it's only mechanical and chemical filtration, I use it with an Eheim 2213 canister filter, which has two stage filtration, including biological. I don't use carbon in this filter as I consider it to be unnecessary. I can also just rinse out the filter pad in the PF-UV25 and use it repeatedly for mechanical filtration when the carbon portion loses its effectiveness.

Together, these filters work quite well, since the Eheim keeps the biological filter in this aquarium healthy, and the PF-UV25 kills off any bacteria or algae spores that can lead to the water's becoming cloudy.

I have been using an AquaTop IL10UV 10 watt inline uv sterilizer plumbed into the output on a Fluval 305 for another aquarium, and it has worked flawlessly for the past four months. The water is crystal clear.

In my experience if you are using a high-tech CO2 lighting system with pressurized CO2, you need a uv sterilizer to keep the tank's water column clear. Otherwise, you'll end up with bacterial and algae blooms every week.

Given the high price of many uv sterilizers, the AquaTop line up is quite affordable and does an excellent job of keeping bacterial and algae growth under control.

I also purchased an AA Green Killing Machine 3 watt uv sterilizer, however, this was more cheaply made, and the uv light crapped out after a month, so I can't recommend it. Especially given the high price of replacement bulbs for this unit.

However, the AquaTop IL10UV has been terrific, and thus far it appears that the PF-UV25 is also a winner. So I can recommend AquaTop enthusiastically. I think that this company is going to give better known manufacturers of hob and canister filters such as Fluval, Eheim and Rena,
a lot of competition in the future. Especially with those aquarists who are using high tech lighting systems and CO2 injection.

It's always a pleasure to find a quality product at an affordable price, and AquaTop has done so with its new line of uv hob filters.


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## Jimmyblues (Dec 16, 2010)

*AquaTop IL10UV And PF-25UV UV Sterilizers*



Jimmyblues said:


> Review on AquaTop PF-UV25
> 
> I just bought an AquaTop PF-UV25 for my 20 gallon planted tank and I like it.
> 
> ...


 
There is quite a bit of controversy in regard to the quality of various brands of uv sterilizers. The detractors of low cost uv sterilizers from companies such as AquaTop and AA (Green Killing Machine) have claimed that the uv bulbs in these units are not strong enough to kill off harmful bacteria and other pathogens which can sicken or even kill fish.

The main point here is that these bulbs are not of a good enough quality. Moreover, there is the question of dwell time - specifically how long the water passing through the uv sterilizer must remain in order for the uv to kill off bacteria and viruses.

These are important issues to consider when purchasing a uv sterilizer.

This author purchased my AquaTop IL10UV and PF-25UV for the purpose of water clarification. These units are installed in planted tanks with high tech lighting systems, injected CO2 and substrate and liquid fertilization.

The result is that prior to adding the AquaTop uv sterilizers, the water was always cloudy, oftentimes even green in appearance from all of the algae that was growing as the result of feeding off these nutrients.

These uv sterilizers, in spite of their cheap quality and low price, have done an exemplary job of removing green and cloudy water - the water is crystal clear.

However, the fact remains that they may not be removing dangerous bacteria and viruses. As such, this author also uses a Vortex D1 diatom filter on my aquariums a few times a month, to polish the water, while removing the dangerous pathogens that these sterilizers may not be removing.

It's been stated that in order to remove such pathogens from an aquarium's water table, the water flow through the uv sterilizer must be between 8 and 12 gallons per hour, which would be much too slow for mechanical filtration. This would necessitate another filter which would have to be run at a much higher rate of gallons per hour in order to clean the aquarium properly and to prevent the water from stagnating.

Moreover, the 8 - 12 gph figure is misleading, in that the more wattage your uv sterilizer bulb emits, the more effective it will be at killing off pathogens, which should allow for a higher water flow.

Of course, the quality of the uv bulb is of tremendous importance here, which is why the better uv sterilizers cost so much more - you get what you pay for. 

As such, this author recommends less expensive uv sterilizers like the AquaTop line, for water clarification alone, since they do a fine job of clearing an aquarium's water and removing algae. 

And I recommend the purchase of a diatom filter for removing bacteria and viruses, since the diatom filter is one of the most effective means in which to do so.

If you want to rely on a uv sterilizer for removing bacteria and viruses, in this author's opinion, invest in a better quality uv sterilizer, with the understanding that the replacement bulbs for these units will be expensive, and if they are used 24/7, must be replaced at least once a year.

As for water clarification, I have found that the AquaTop IL10UV inline uv sterilizer ($40), and the AquaTop PF-25UV hob uv sterilizer ($54.99) do a superb job at a very reasonable price. They are fairly well constructed, easy to maintain, and the uv bulbs are inexpensive to replace - $11.99 each at TruAqua.

As for whether or not these units also offer effective bacteria removal, I must conclude that if the cloudy water in my planted aquariums is due to large amounts of bacteria feeding off the nutrients in the water, and the water becomes clear after running my AquaTop uv sterilizers, then these uv sterilizers must also be at least somewhat effective in killing off bacteria - otherwise the water would remain cloudy.

However, given the controversy over expensive (quality uv bulbs) vs inexpensive (cheap uv bulbs) uv sterilizers, I would prefer to use the AquaTops exclusively for water clarification and algae removal, and rely on the Vortex D1 for removing bacteria and viruses, since the Vortex, given it use of DE, has a proven track record for doing so.


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## zdnet (Aug 13, 2010)

Jimmyblues said:


> There is quite a bit of controversy in regard to the quality of various brands of uv sterilizers. The detractors of low cost uv sterilizers from companies such as AquaTop and AA (Green Killing Machine) have claimed that the uv bulbs in these units are not strong enough to kill off harmful bacteria and other pathogens which can sicken or even kill fish.
> 
> The main point here is that these bulbs are not of a good enough quality.


Do you have a link to the argument? 

I myself have used various brands of UV sterilizer including Helix Max, The Green Killing Machine, and JBJ Submariner. Some charged a much higher price on the UV bulb. So I used the lower price replacement bulb. UV quality was never an issue.




Jimmyblues said:


> Of course, the quality of the uv bulb is of tremendous importance here, which is why the better uv sterilizers cost so much more - you get what you pay for.


Economic 101: Pricing is about the balance of supply and demand, NOT quality.


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## livingword26 (Oct 28, 2010)

I don't know about Harmful bacteria, but I had a bacteria bloom once that made my tank almost as white as milk. I couldn't make it go away no matter what I did. A Green Killing Machine from Petco cleared it up in 24 hours, never to return. I did purchase the Aquatop UV HOB. It has worked well for 4 months so far. I haven't really had anything to put it to the test, but thats why I got it in the first place.


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