cannister filters!!!

[julest]

Can anybody help? I've got an interpet (hydor) prime 20 external cannister filter.It has avery coarse grey sponge at the bottom,and active carbon media next then 4 fine white wool sponges.do I clean all the sponges together or just one at a time and will cleaning the sponges affect the colonising bacteria?
I'm sorry to be asking such a basic question but the maintenance instructions are'nt very clear!!Also if anyone uses this type of filter how often should I change/clean the sponges/media?...again the instructions are'nt very clear!!!

Thanks for the help

julest

[Cougra]

You can clean all the sponges at once, however only clean them out by swishing them around in some old tank water to get the mulm out. NEVER clean them under tap water! Any water that has drastically different parameters will negatively affect the bacteria. When you clean the sponges they will never be the same colour as the were when they were new. They don't need replacing neither, just a gental cleaning.

I don't have that particular type of canistor so I can't tell you how often it will need cleaning. Plus there are a lot of variables in how often a canistor needs to be cleaned such as what type of tank you are using it in, what type of fish you have, how many fish you have, how you feed the tank...etc. Try cleaning it once every week or two to start with and see how much debris builds up in the canistor and the sponges. If you don't have much in there then you can wait a little longer between cleanings, if you have a lot of mulm in there then you need to clean it more often.

This regime will also need changing when you add new or different fish to the tank until you get used to the amount of waist they produce.

[julest]

Thanks cougra.

julest

[DaveK]

A better question might be, "Should I be using a canister filter at all?" Personally, on a reef system, I prefer not to use them, since they tend to become dirt traps and nitrate factories. Also, since it's a sealed unit, it becomes a big oxygen consumer once bacteria start growing in it.

If you do like canister filters, I recommend cleaning them weekly. I don't recommend using a canister for biological filtration, so unlike Cogura, I would clean the filter in fresh water to kill off the bacteria. Of course, this does mean you must use something else for biological filtration. I prefer using live rock, or using a wet/dry filter if live rock isn't being used.

[Reefaholic]

I'm with DaveK and IMO canister filters are a waste of money. I think more people than not will say the same thing. They are really nothing more than a "nitrate factory " If it where me I would get rid of it now and save your self some trouble and $$$ in the long run!

[gussy]

I have two large cannister filter in my goldfish tank and they get rid of all the ammonia and nitrite, but Nitrate is at 30 by the time I do my bi-weekly 50% water change.

Don't use the cannister filter for the reef tank. Eheim has a wet/dry filter that looks like a cannister filter...that is if you absolutely gotta have one.

[BoomerD]

That Eheim Wet-Dry canister is just another nitrate factory, albeit a nicely made one. Leave the canisters for the fresh water folks. They just cause too many problems for reef tanks. The only exception, is if you use them for occasional carbon filtration only. I have a Magnum 350 that I fill with good carbon, run it for about a week, then remove it before the carbon & prefilter have a chance to become a biofilter and start producing large amounts of nitrates.

[julest]

Thanks for all the advise guys.Can you advise what would be abetter option.My tank is a 55usg bow and has around 45lbs of live rock.I dont have any thing but fish in at the moment.It has an internal Juwel filter as well as a protein skimmer and has about 2" of crushed coral as the substrate.The cannister might be the reason why my nitrates are at 25ppm and no matter how many water changes I do I don't seem to be able to lower them.All other readings are spot on.


Julest.

[DaveK]

Like anything else in reef systems, there are a lot of way to go from point A to B. So the method I'm going to recommend here is not necessarly what someone else would recommend. Yet, at the same time, we may both be correct or both of us wrong.

Before anything else, you have to decide what direction you want to go. If you are going to keep only fish. nitrate is not too much of a problem. If you want to keep corals, clams, and similar inverts, nitrates must be controlled.

Assumeing you want the later, and have the money to spend changing the system, this is what I would do.

I would replace the canister filter and the Juwel filter, which is more or less an internal canister, with a berlin type sump, an overflow, and a return pump. If chosen carefully this can all be placed below the tank in the stand.

The berlin system usually uses a filter sock for mechanical filtration. Since the sock is easily removed and replaced, it's easy to change or clean it often. This prevents the "nitrate factory" effect and oxygen usage of canister filters.

Berlin systems sometimes use a sponge filter after the filter sock. If the sponge is used so the water flows across the sponge rather than through it, ths sponge can remove some nitrate. If water flows through the sponge it's another mechanical filter, and will become a "nitrate factory" if not cleaned often.

The whole key to this system working is good quality skimming, since skimming is the only part of the filter system that removes stuff before the biological filtration has to deal with it. By keeping this out of the system, nitrates are not created. You may wish to check how good your current skimmer is.

Biological filtration is done by the live rock. You may want to add some additional rock, but you may not need to do this.

One other problem area is your sand bed. That is also a "nitrate factory" and dirt trap in it's current form. I recommend you either remove most of it, just leaving enough to just cover the bottom, or go with a deep sand bed of at least four inches.

The deep sand bed will have enough depth so that it can break down nitrate. However, this is a slow process,