If your buying the smaller models, I find them to work very well. I wasn't however fond of the larger models. I had the 150 and mine was very noisy and stirred up the sand too much. If the flow were able to be adjusted I could've dealt with the noise and it probably would've cut down on the noise as well. All in all a good filter, if you dont mind some noise with it.

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*Keep Smiling, It Makes People Wonder What Your Up To*

Tanks-
55 Gallon--On Hold, In Storage...
20 Gallon High--Tetra and Cory's
5 Gallon Hex--Guppies (3 Female, 2 Male)
2.5 Gallon Mini Bow--Future ADF Habitat

I have the penguin 350 with dual biowheels. It seems to be working really well and it definitely starts more easily than my emperor 40. However I really dislike the fact that there is no way to control the water flow. The other drawback is that the output lips are very short and to avoid splashing it requires a very high water level. Regardless, for the price it works really well.

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A Quarter Fathom Journal

This is my fav. HOB filter... pretty cheap sometimes clogs.. i would advise not to use on SW

This is Marineland's economy version of it's Emperor filters. You get what you pay for with these filters. I had my Penguin for maybe 3 months when it started to make a loud noise. A careful inspection revealed a bad impeller. I replaced the impeller and within 3 months that one was bad as well. I will personally never buy a Penguin filter again. I want a filter that I don't have to replace the impeller every 3 months. I got 6 months use out of my Penguin, it has been collecting cobwebs and dust ever since.

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Considering a Marine Aquarium? A Breakdown of the Components, Live Rock, Cycling a Marine Tank

"The capacity to learn is a gift; The ability to learn is a skill; The WILLINGNESS to learn is a choice." - Unknown

I think the bio-wheel feature out weighs all negatives. I bought a 350 for $10 used. It needed a good cleaning so obviously was used for a long time. I have had it running now for well over a year, and it still works as if it were brand new. The only draw back is replacement cartiridges are expensive. So I bought one cartirdge and ripped off the pad. Now I just cut a filter pad and place it on the cartridge. Expense problem solved. Only drawback is you have to buy a cartirdge for Chemical filtration. I never do, the biological and mechanical work fine.

i have a 100 gallon tank w/ 2 penguin 350's the filter cartridges were to expensive so i customized the filtering system with a few different items that i found in Drs. Foster and Smith. my filters are way more effiecent now and also filter out heavy metals, ammonia, clorine ,waste products from the fish and their food and particulates and keep my tank crystal clear. the cichlids love it and they create great circulation in my tank. all in all a great filter with easy maintenance

This is a great HOB...the ability to supply aeration to nitrifying bacteria bia the biowheel is a great feature. The bad aspects of this filter is the need to replace filter media often, which can be pricey. Also, if a small amount of sand gets stuck in the impeller, this causes complications...you may have to take the whole filter apart to clear the debris.

I had one of these on my tank for a day and that was it. It was just way too noisy, it could be heard over my TV. I even went as far as to buy a new impeller for it and it was just as noisy. I had the 100 series and if it wasnt for the noise it would of been a great filter.

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55 Gallon Freshwater

I like these filters a lot. The newer models have great water flow and a biowheel. Unlike some of the other reviews, I've never had mine clog (I wonder what they were clogging with). They are prone to a bit of waterfall noise. They have a sweet spot where they are very quiet, above or below that you can get some water noise. There is however no easy flow control. You can raise and lower the intake bar to change the flow but it doesn't always work.

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75G Planted Blue Themed Community Tank:
Neon Tetras, Blue Platties, Blue Guppies, Blue Snails, & a pleco
with 4 hang off breeder tanks for Blue/Red Platty Project

I specifically asked the woman at the pet shop which of her brand filters were the quietest. She sold me this brand. I have the one for 20 gallon tanks but I have a 10 gallon tank.

I live in a studio and I can hear the impeller everywhere in my small space. One of the things I like about my apartment is how quiet it is. Or now I should say "was." I'm hoping I can return this worse than worthless annoyance. I rode my bike over 6 miles to buy this and now I have to go back.

Ive had one for yrs.Although a bit noisy it works great.

A bit better than the Emperor (odd, I know) but still noisy and not much room for media in this filter. There are better HOBs on the market.

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Originally Posted by i_am_511

Lighten up its just the internet its not like someone came in your house and punched a baby in the face.

I have had the Penguin 200 for about 3.5 years now and have never had a problem whats so ever. Great filter overall keeps my tank spotless. Does get loud when water get low. I am very satisfied with this product.

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Shaunjr_89

I like the biowheel a lot, but I've noticed after just a few months that all (one 350 on the 55, had 2 on the 90, one 200 on the 30) the biowheels now turn very, very slowly and sometimes cease completely for a few seconds, even though the cartridges are new or recently cleaned.

They can be very loud unless the water level is flush with the output.

When restarting the filter after a water change, it takes a while to prime. Often I have to pour a couple specimen cups worth of water into it to get the biowheels moving.

Works really well was the biggest and best lfs had. 6 pack of filters around here where $20 but i've found them on line for $10 so now its just costing me $3.33 a month in filters as for the waterfall sound its fine with me it helps me sleep

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55 gal. freshwater
4 guppies, 3 painted glassfish(bought before i realized what they do to them), 3 glofish, 1 female betta, 1 red velvet swordtail, 1 redtail shark, and 2 banana plants