Thoughts on canister filters

[aqua_holic]

Kind of. The efficiency of the bacteria is a function of pH, which is why people with low pH can have trouble cycling. Also why it's suggested for some to raise the pH with baking soda during fishless cycles. So the bacteria colony of a tank with a pH near 8 will be much smaller than that with a pH of 6.5, yet do the same job.

Too, the turnover rate plays a role on the colony size. The faster the water is turned over, the lower the standing ammonia concentration entering the filter, and the less bacteria will be present. A slower turnover rate means more time for the ammonia to accumulate, which means a larger colony is needed to process it all. That's the fundamental reason why HOB filtered tanks need a higher turnover rate than canister filtered tanks - to make up for the lack of media they hold.

 

[Delapool]

I forgot about ph and temp. I'd imagine it would be pretty hard to compile but have never seen a study on it. The main reason I've wondered is that I've read the biomedia pore spaces are meant to get blocked up with gunk/dead bacteria and the media has less efficiency. I've always taken that with a grain of salt and never replaced it (although done water checks just in case). I can only figure I have so much media it doesn't matter or the media gunking up is not so important? The blast with the hose removes loose stuff but it's not a pressure cleaner.

 

[aqua_holic]

Yes I've read that too, about the media getting clogged. I've not concerned myself with such notions because like you, I haven't had a need to. It's a theoretical argument that in all likelihood is legit (IMO)....but whether or not it has an appreciable practical impact is another matter. I've not seen any.

 

[Delapool]

I don't worry about tap on media. I routinely clean it under tap, that is how you get it the cleanest. I don't think tap is as bad as you would think, after all you can't put tap water on your kitchen counter to sterilize it, so why think a few minutes of rinsing would do the same thing.

I would be more worried about running it under really hot water.

.

I thought about that and could well be true. Public pools have higher chlorine levels (although I guess they need it lol) + every summer here there are warnings about the temperature getting too high and encouraging bad bacteria in plastic kiddie home pools (which would be filled mainly from the hose). Also we used to get drinking water contaminated every so often (can't remember what it was - some sort of bacteria or algae) and they had to shut the water line down (I assume to treat with stronger chemicals).

 

[Delapool]

Yes I've read that too, about the media getting clogged. I've not concerned myself with such notions because like you, I haven't had a need to. It's a theoretical argument that in all likelihood is legit (IMO)....but whether or not it has an appreciable practical impact is another matter. I've not seen any.

Yes, I think I have seen one article on hetero(?) bacteria depositing a slime - could well be way off base there, will see if I can find it tonight.

I could just see that - yes, it can happen so the marketing label says change your media (and in the fine print - but it takes 5 years...)

 

[aqua_holic]

I've seen people claim biomedia to be useless for that reason, going strictly with mechanical media. I've also seen people claim mechanical media to be pointless, advocating using only biomedia.

I stick with my setup - fluval ceramic prefilters first, then sponge, then biomax.

 

[Delapool]

Lol - I guess there are many ways to skin the cat.

 

[aqua_holic]

That there are

 

[CoronaBlue]

There really isn't a strict way of doing things. What works for one might not work for all. I rinse my mechanical in tap and bio in tank water. I've never had an issue and I run 3 canisters and 2 HoBs between my 2 tanks.

 

[ProAquarist]

I don't think HOBs need a higher flow rate (especially since most are slower than canisters and still manage to keep ammonia and nitrite at 0ppm).

In the end I think most tanks need less biomedia than we would believe. There are all sorts of factors that dictate how many bacteria there will be and how efficient they are. Flow rate, temp, pH, surface area, etc. all affect it but in the end it is really hard to not have enough biomedia for bacteria. They will colonize what little they have and do their job. In most cases if there is insufficient filtration it is caused by a lack of mechanical filtration, not biological. The tank will look bad, the water won't be clear, there will be debris all over the bottom, and yet there still won't be any detectable ammonia or nitrite.

 

[MatthewsDyer]

I have a 55 gallon planted tank with co2 and want to know what canister filter to buy? What would you guys recommend?


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[Huro]

Hi Mat, sorry for the late reply to your question. To help everyone here give you the best advice I just have a couple of questions for you. What is your price range, and do you want a system with UV or not?

 

[MatthewsDyer]

I actually just bought an Eheim Ecco pro 2236!! Is that a good one?


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[Huro]

Although I personally do not own an Eheim many folks do and are quite happy with them. I did look up the specs for this filter and it shows a 198gph flow rate, is this correct?. The reason I ask is because for a 55g you should be looking for at least a 220gph flow rate, possibly higher depending on what your stocking.

 

[MatthewsDyer]

Ya i do have a 55 gallon!! But the guy at my local fish store recommended it to me!


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[Huro]

I certainly do not want to speak poorly of people but you can find many posts in the forum regarding bad information that was given at the LFS. If it is possible I would recommend returning the Eheim in favor a model with a higher flow rate, at least 220gph for your 55g tank. Although some may disagree the general rule of thumb is the flow rate of your filtration being at 4x the volume of your tank.