HCA: Hermit Crab Association

I went to petsmart and petco, and was trying them all out in the store. But it's really hard to tell the differences, so I ended up buying one of every brand, bringing them home, and spending all night plugging each one in over and over again trying to compare the noises and sounds to see which was the quietests (or rather, most tolerable). And I'll return the ones I don't want.TopFin 50g, 14$:This was the first one I got. I'd returned it when I got the others, so I don't have a direct comparison. But it was pretty loud. You didn't have much trouble hearing it all over the floor.Profile 50g 12$:This was was noticably louder than the rest when I was trying them out in the store, so I didn't bother bringing one home. It's also the cheapest brand in terms of price.TetraTec 60g 40$:This one was pretty loud. I think it's probably about the same as the TopFin one. What is weird is that with just this air pump, the nozzle that is attached to Tropicaire #1 is always much louder and has more rattle than the nozzle attached to Tropicaire #2. It's not the nozzle, because if I swap sides, the sound swaps. This model has flow adjuster knobs for each side. I can turn down the loud side so that it becomes pretty quiet actually, but then there's no air flowing out of that airstone.Penn Plax 2K5 80g 18$:This one was actually a pleasent suprise, for being on the cheap-half of the scale. At first it seemed almost as lound as maybe the topfin or tetratec. But later on when I was doing some muffleing experiments (placing it inbetween two pillows under the tank), it came out fairing pretty well. The sounds it made were muffled into a lower humm that was quiet tolerable. Considering that this is a 80g pump, with a sound that is slightly more tolerable than the TopFin (which was cheaper, but only 50g) and the TetraTec (which was 60g, but costs twice as much), it seemed like a good option.Whisper 60g 29$ (actually 25 with PetPerks):This is also a Tetra product. The main difference between this one and the others, is that while the others have a buzzing noise that has some more medium-range frequencies, the whisper noise is pretty much all low-range frequencies. So it makes for a bit more pleasent background noise (my ears seem to more easily take to a low-hum in the background that a medium-pitch hum). The problem is that these low frequencies seemed to vibrate through the tank and wall more. when I stand on the other side of the wall from the tank, I can hear the low hum a little louder as it resonates through the wall. But with my pillow-muffling in effect, there's some spots in the living room I can't even hear it above the waterfall or fridge in the next room.But I want to get back to the Penn Plax for a second. Because the medium frequencies are muffled better by the pillows and the tank stand walls, so with the piillow-muffling in effect, the result is the same low-hum as the whisper. Maybe half a decible louder in the front of the tank, but it doesn't resonate through the walls quite as much. And it's 13$ cheaper to boot (though the Penn Plax only has a 90 day warrantee, compared to the 1 or 2 years on most the others).Hagen:None of the hagen ones I saw went above 30g. So I didn't even bother.Rena 75g 47$:The most expensive one. The main problem with this one is that there's only 1 outlet, so it can only run one tropicaire. I connected both tropicaire's to it using a T connector, but one of the air stones must be tighter than the other or something, because air only blows out of one, and not the other, in this configuration. So if I were to choose this model, I'd either need two of them (100$!), or ugrade to the 160g model which costs 70$!. There was a big difference in sound. The Rena one has almost no low-hum, it's all a higher medium pitch buzz. It's about the same loudness as the others. But the difference is that this high-medium pitch buzz is muffled very well just by closing the door to the tank. After adding the pillow-muffling, the result is extremely quiet compared to the others. In certain parts of the room, you can easily not notice it.So, as you can see, there's no clear choice. For my particular needs, I have a 92g tank, and I have two tropicaire humdifiers which are rated up to 55g each. But I'm not sure I need a full 92g or 110g of humid airflow. With two water falls and moist coco-fiber, I dont' think humdity is a problem at all. But I definitely need inflow of fresh air to prevent the air from getting stale and smelling like it always did before. So I'm thinking of getting one pump with 2 outlets to power the two tropicairs (since it appears that the difference between the two airstones prevents a T joint from working). And then another pump to just pump bonus plain fresh air into the tank. The combined total of them should be over 92g.The Rena 300, though desirable because it's noise is the easiest to muffle, won't do becuase I'd end up spending 100 dollars. Is the difference in noice between the 18$ penn plax and the 50$ Rena worth 32$? That's the question.I also spend the longest time trying to decide whether the whisper or the penn plax was quieter. It's really hard to tell. Since the penn plax is slightly higher-pitched than the whisper, and the penn-plax has 20g more air flow, it's not a direct comparison. I think the whisper was a clear winner in a no-muffled contest. But with the pillow-muffler on, it was really difficult to tell them apart. And the whisper was 7$ more, and only 60g vs 80g. So I also have to take into consideration that if the penn plax had been tuned down to only 60g, then it probably would have been noticably quieter.With an 80g penn plax, I get 40g to each tropicaire. But iwth just a 60 or 50 of the othe brands, I only get 25-30g to each tropicaire. So it seems that for 7$ cheaper, and about the same sound, I get more air.I wonder how the TopFin would have compared in the pillow-muffler test though, since I never got a chance to try. maybe I'll pick it up agian on the way home.How does everyone elses' experiences compare with mine? Any final thoughts or recommendations? Specifically, what do you feel on long-term reliability of the units? The only thing that worries me about the penn-plax is that it has the shortest warrantee of all the models, only 90days.Also, does anyone know how much gallons rating I should have for total air flow (including the tropicaire and pure fresh air) going into the 92g tank in order to keep the air fresh and prevent mold and smells?JMT.

I was reading up what few other reviews and info on air pumps I could find on the web. I noticed that it says that the penn plax k5 (I think this used to be X5 in previous year's models) is supposed to have 2 settings, one for quietest operation, and one for max output. But I can't find any switch or dial or anything on the unit. And the instructions don't mention anything. Does anyone have any idea how to adjust it?

quote:Rena 75g 47$:The most expensive one. The main problem with this one is that there's only 1 outlet, so it can only run one tropicaire. I connected both tropicaire's to it using a T connector, but one of the air stones must be tighter than the other or something, because air only blows out of one, and not the other, in this configuration. Not tryin' to sway you on this, but there are a few factors that would cause the problem you saw with one blowing and the other not.First and foremost, the longer the air hose, the more resistance against the pump trying to blow through it. If the two air hoses are not EXACTLY the same length, the air will take the path of least resistance, and thus only blow through one stone.If that's accounted for, then different types of airstones, age of the airstones, different types of hose, and clogging in the hose will have similar results, as well.--Another few things to take into consideration:I assume, from how you've been writing, that the air pump is to be located in the stand of the tank, yes?Keep in mind that, as above, the longer the hose, the more resistance - if you have four feed of hose, versus a foot or two, you will have DRAMATIC differences in output! Try it, if you have extra hose leftover, try to find a way to rig it so that you have only a SHORT path for the air to travel - seriously, grab some extra hose and give it a try - set the devices on top of the tank, if necessary, just to see the difference.In an aquarium, folks generally use an air pump to force air a short distance (say a couple feet, a few feet at most) down into the tank filled with water to make turbulance and aeration for fish.These ratings, 50-gallon, 80-gallon, etc., are really not in any way an accurate way to tell you how much air is comin' out of the pump. It's only telling you the manufacturer's idea of what size tank the air pump is adequate for. This may differ dramatically from manufacturer to manufacturer, even to the point that one pump, rated for 50g by one maker, pumps much more air than another pump, rated for 80g, by another maker. If you can contact the manufacturers and get any specs on how much psi, bar, or whatever, the device produces, that would be more helpful, I'd wager.Lastly, if the airstone is ABOVE the height of the air pump, you really might want to invest a few bucks into an "airline check valve" to prevent a back-siphon, should the power go out or something else and a siphon be created - this could cause anything from just a mess of water to be deposited on the floor, to a real electrical hazard. It might be worth it to you to have such a device in the airline. Otherwise, find a way to have the pump ABOVE the height of the airstone to prevent such a scenario.Just some ideas, hopefully useful!

Er, and lastly, since you're NOT using the air pumps in a conventional manner, you may not at all need anything even anywhere near rated for a tank of your size.... keep in mind, the 50g, 80g, etc., ratings are for using the pumps to create turbulance and aeration in a fish tank setting.

Yep, the hoses are the same length, and brand new and clean. The distance from the pump to the airstone is probably less than 3 feet of tubing. The tropicaire's are also both in the tank stand next to the pump. From there, I have a longer hose that takes the humid air up to the tank. Probably around 8 foot. Again, same exactly length for both, and brand new clean line.The instructions on the tropicaire specifically say to get a pump rated for the size of tank you have. I read one website that says that this represents cycling the air in the rated tank once per hours. Previous posts on this board about the tropicaire recommended getting a pump rated for *twice* the size of your tank.Thanks,

Aaaaaah, gotcha.Still, it would probably be beneficial to find out just what kind of output each manufacturer thinks is "right" for x-sized tank.... Such discrepancies are very common, even in filtration and heating choices for aquaria.

quote:Probably around 8 foot. If the humidifier is roughly air-tight, this 8' distance is probably seriously affecting the amount of resistance on the pump - it might be fun to play with to see how different lengths of hose on that side of the device affect it.