Imagine the below situation:



Say both tanks runs for a week. Am I right to conclude that both tanks will have 0 ammonia, 0 nitrite, and the same amount of nitrates, the only difference is the second tank is dirtier?

correct, the second tank would only trap the particles on the sponge but there is no place for it to go out of the tank, i personally think that the nitrate lvls would get higher in the second tank than the first.....my

is it because of the debris floating around in the second tank?

oh yeah, i mean you look at other filters, they tank they debris out of the tank and then you rinse it off, but with sponge filters it will suck up the debris but its still in the tank water, not going out anywhere

Do you think the nitrate levels would be much higher or just a bit?

FYI, I have a tank with a sponge filter and I've found that in time the debris will eventually dissipate any leftover waste matter will congregate under the filter, leaving the tank quite clean. Still, not quite as clean as my tank with the canister.

For me I clean my filter once a month, for Canister is once every four months. So debris stay in the filter box for at least one month.

I am interesting in this topic since I saw a lot of people from oversea just use sponge filter for their gf(fancy) tank.

Isn't 4 months a bit long?


My intentions exactly. Except for the obvious superior mechanical filtration, what else does a canister (or HOB or other "gadgety" filters) have advantage over a simple sponge filter?

Store recommeded to clean every 6 months... but I decided to do it every 4. How often do you clean it?

But we should really focus on the main topic..

Not that I know very much about it, but I'd surmise that the actual removal of the waste would be advantageous in that waste left in the water can create toxins after a time?

Interesting topic.

Lisa

But we don't clean our filter once a week (we are not suppose to, this will kill the BB). So debris is staying in the same water from our tank. Just in the different location, isn't it?

This is true. Hmmm. I don't know, I guess my 'gut reaction' is that there is some advantage to it being removed from the main environment. Maybe I'm thinking that the waste has more opportunity to go 'stagnant' if allowed to simply collect inside the tank?

Again, interesting topic and I'll be watching this thread. I really need and want to learn more about the mechanics of filtration.

Lisa

Actually, I think I have to disagree.

The tank with the 400gph has 400 gallons of water running past the beneficial bacteria that are on the media. They are constantly exposed to new, ammonia/nitrite laden water as the water is pumped past. The bacterial colony will grow to the size needed to process any/all of the ammonia/nitrite that passed by.

In the second tank, the beneficial bacteria are only given access to a very small volume of water per hour. Air driven sponge filters run very slowly. Depending on how clogged the pores of the sponge are with mulm and waste, the air driven sponge runs only a few gallons an hour. The sponge may be "fully cycled" but incapable of dealing with the waste of the two fish. So much depends on the size of the fish, the amount of food being fed and the amount of "waste" sucked or left in the tank. Beneficial bacteria cannot process ammonia/nitrite unless they have contact with the water that carries them.

It is for this reason that in an air driven fry tank, I find that I need to add a power head to the sponge at about 3 weeks of age - to deal with the waste. At about 4-6 weeks of age, the fish need even closer to 10times turnover an hour.

The beneficial bacteria cannot process ammonia or nitrite if they do not have access to it. To get them access, the water must pass through the media. The more that passes, the more than can be potentially processed.

If you were to stick the intake of the 400gph filter down into the sponge filter - and add no media, no biowheel or anything into the case of the 400, you would get the same filtration in the tank using the sponge as the media or the clam shell as the media. (assuming the sponge was kept relatively clean such that the mulm did not create blockages, etc).

I also want to know what is the life spam of fish in the second tank.

The life span of the fish would be unaffected if the water changes and such were kept up to keep the parameters under control. More would need to be done for the second tank, or to run it green water for good health. Parameters kept in a good fashion would result in the same health and hardiness for either tank.

If the water was allowed to have a buildup of ammonia or nitrites, as for any tank with such pollution, the fish would be stressed and subject to disease and parasites. It matters little HOW the parameters are kept under control - just that they ARE.

I'm not disagreeing with Koko about the nitrate levels being higher, but I think that the reason why there would be more nitrates in the long run is because it's difficult to remove all the mulm from a sponge filter, as it is not 'contained' and is located in the main area of the tank, -when you take out the filter to clean, some residual mulm remains in the tank, which continues to release nitrates into the tank, where as in a cannister, for cleaning you remove the whole cannister from the rest of the tank, so all mulm (well a lot more of it) can be rinsed off during cleaning, hence more nitrates being removed from the system with each clean. I don't think that there would be higher nitrate levels just purely from the physical difference between the filter types.

I agree with Carol, you need to have the same volume of water passing through the filter media to get the same level of ammonia conversion.

Hmm I think it's not that low. A single-outlet air pump would normally pump 30-50 gallons of air per hour, no? Still lower than a canister of course, but not bad.

Say Carol, if I were to stick the intake tube of a canister (which case is normally filled with media) into the sponge filter, I don't have to clean the canister as often, right? Cos some of the waste is trapped in the sponge?

EXACTLY! That is what pre-filters do for you. I have that on most of my fry tanks - soon to be all. I used an air driven sponge filter for the tiny fry. They then graduated to a small powered pump pulling water up through the sponge. The next step was a smaller than normal (low gph) cannister with the seasoned sponge over the intake. I squeeze out the sponge every few days, but have not had to service the cannister yet on any of the tanks. A 165gph cannister works well for a 30 or 40 gallon tank heavily loaded with 1/2 - 1 inch fry.

Another wonderful thing that happens with that setup..... the cycled sponge from the sponge filter automatically cycles the media in the cannister, for the bacteria are pre-filter. They travel easily and well to the cannister media even in a UV treated tank.

The reason why I made this thread is that I want to find out why does so many Asian hobbyists only use simple air-driven sponge filters in their tanks, and partly because I'm kinda sick & tired of cleaning my canister, such a job, and if I can replace it with sponge filters then why not? Besides, I do 100% water change (almost) every week so a sponge filter should be sufficient, right?

From the replies, I now conclude that using sponge filters alone might not be enough, and canister filter has its benefits. Since my aim is to reduce the maintenance frequency of my canister, I think I might follow Carol's advice and attach a sponge on the intake of my canister. One question though: Will the gph of the canister decrease?

Yes - it will. But there are "pre-filter" sponges you can buy that are specifically made for this type of application. They are a courser sponge - so there is more water flow through them than in the tighter sponge that is typically used for biological media....

Lets see.................

These guys have the best selection and the best prices I have ever found. I do not know if you can find this sort of thing where you are, but these are REALLY good sponges - and the "pre-filter" ones are just what you want.

http://www.jehmco.com/PRODUCTS_/FILTRATION...ge_filters.html

Thx daryl

For that matter, I do not see why you would not have both biological success as well as a lowered need for service if you were to strip your cannister of all floss/pads etc. that are designed to trap larger particulate. Even the larger ceramic pieces that are designed to break up the flow and allow large particles to drop from the currents and remain in the filter could be removed. Pack the cannister itself with only media for bacterial platform.

Use the pre-filter sponge as your main catch-all. A sponge is really easy to pop off the intake and squeeze out really really well anytime you wish.......

Sorry I am wading into this debate late, but I would like to chime in on the issue. The nitrification process will be rate limited by one of several factors. These are: 1) amount of ammonia present; 2) amount of bacteria present; and 3) amount of oxygen present. The filter can only affect the amount of bacteria present (i.e., surface area for colonization) and the amount of oxygen available to the bacteria (i.e., flow rate). The amount of ammonia present is another matter entirely. If the filter has sufficient capacity to process a given load of ammonia, then the "parameters" will be zero. If it doesn't, then you will find ammonia and nitrite present.

So, it is hard to answer your question (which will have higher parameters?), because the answer could well be that both will yield zero, if the ammonia loading is below the capacity of both filters . However, that is not the question that you really want to ask. The real question is, "Which filter has the higher capacity, or processing ability." The answer to that question is the cannister.

Why? While both can provide the same surface area, the cannister with its higher flow rate will deliver much higher levels of oxygen (and ammonia, as Daryl points out). Its likely that the amount of active bacteria in the sponge will be limited because of suboptimal growth conditions.

That's not to say that sponge filters aren't good biological filters, and they are certainly cost effective. However, I'd have to say that the cannister will have a higher waste processing capacity.

It is my observation that I tend to see evidence of biological growth in my cannister sponges than I see on my ceramic rings. I can appreciate your concerns over cannister maintenance, but since I've gone to the Eheim and Rena, maintenance is a snap. I mostly clean the bottom of the cannister out, do a quick backflush under the faucet (well water), and a fast sponge squeeze and back in service.

Sorry for being a bit long winded.

Dennis

now i agree with the fact of having a pre cleaner to a canister....

Some canister depending on the brand of them can be a pain in the butt, for example Fluvals, the hoses on this brand are like vacuum hoses and the collection of muck building up in the hoses can cause a problem...Most of the other brands have clear hoses this can cause an algae build up if the light hits them, Eheim was the only company to use green colored hoses, this will cut down the light on the hoses.....sorry to get a little off topic but just wanted to state that it would depend on the canister too.

But the main point it comes down to is what is the water parameters when it is all said and done, me personally like to keep the gunk away from the fish, so that's why I'm a canister lover and very picky on what kind i have...

Great topic by the way

Indeedy I do clean my canisters once a week or even more frequently if I can. I have a sore back!

The issue I find with the sponge filter alone is regarding the total dissolved solids and mulm in the tank where harmful heterotrophic Aeromona bacteria feed off it and can quickly build to levels which overcomes the fish's immunity. There is really no difference in that situation if the mulm is inside the canister instead either, but the addition of a UV clarifier/sterilizer on the canister outflow would kill any Aeromona before they returned into the tank. It doesn't eradicate them completely, but it does help control their levels at a safe amount. This is an easier setup than adding a separate UV and pump on a sponge-filtered tank I think. The frequent, often 100%, water changes by Asian goldie owners achieves the same purpose of keeping those bacteria levels down.

I also believe the presence of a pre-filter sponge would mean the beneficial bacteria colonies would simply grow there on the sponge (exactly as on an air-driven sponge filter) instead of inside the canister itself where the rest would starve and die off. First-served, so to speak.