bioload and filtration

[Tooj]

hi there, i have a question about filtration that you guys might be able to shed some light on.
with a HOB filter, theres usually 3 filter steps...my understanding, and please correct me if im wrong, is that the activated carbon is not really needed once the tank has been fully cycled...? ive read threads were people suggest that the carbon be removed entirely.
On that note, ive always provided my tanks with more filtration then the tank needs (according to gallons). but what if i want to increase the filtration even more? would taking out the carbon in the filter (currently have an aquaclear 20 and a topfin 30) and adding another sponge increase the amount of bioload that my tank can take? because isnt a filter really there to circulate the water and sustain benificial bacteria?
and in the case of my topfin 30 filter...it has alot of room in it...if i put sponges inside of it would that help as well? but that the heck, why not go all the way...? wouldnt having a mound of sponges inside my tank increase the bioload capacity that im able to have? (room and space issues aside)
i welcome your thoughts and comments! thanks

 

[nanu156]

ummmm..... ok so you are right on the use of a filter, it is to A. move the water B. catch the floaties and C. help the bacteria colony.

you actually don't need the carbon at all in the filters unless you are removing meds.

there is no room in an AC filter for another sponge.

While your theory about having more bacteria to sustain more fish i believe that the amt of bacteria you have depends on the amt of fish waste you have, that being said the gravel and decor will host plenty of bacteria for a tank that is not too crowded the filter just adds a second buffer.

There really is no advantage to the second HOB filter other than to drive up your power bill and provide a fail safe if the filter goes out. The AC is unlikely to go out they last forever.

Stocking density impacts nitrates if you are too densely stocked as long as you don't crash the system (by say doubling your stock over night) you will grow enough bacteria to eat as much poo as the fish can produce, the trouble is actually that the nitrates are not eaten by bacteria and have to be removed by cleaning the tank. So when your stock gets too high the water gets toxic not because there isn't enough bacteria but because there is too much of the third step in the cycle.

You can play with your stock levels as an advanced aquariust, basically you will hit a threshold that you can manage you will know you are at the max when your stock levels manage themselves (fish start to die)

I don't think aquadvisor is the end all be all for stocking plans but i would say as a rule of thumb 1" of fish/gal works well, if you go beyond this 1.5-1.75" of fish/gal would be a real heavy stocking plan.

 

[Sageofstupidity]

I am new to this but I believe carbon does in fact help with filtration. The three-stage filtration are biological (bacteria), chemical (carbon), mechanical (floss-type media) someone correct me if I am wrong. If you want to increase your filtration use one of your extra filters, or upgrade to a filter with more gal per/hr. Do some research on filters, it seems canister filters are among the best and I believe they still use carbon. I guess this is a matter of H.O.B. from the sounds of your post. Also if you have gravel in your tank look into an undergravel filter, those can have powerheads attached and they basically create a space between your gravel and the bottom of your tank to make a better bed for the bacteria, add a powerhead for more water flow and you get a more oxygen rich gravel bed for the bacteria to thrive. Hope any of this helps.

 

[ryanoh]

Carbon does "help," but only to a certain degree. You really only "need" it to remove medicines like nanu said. It will absorb some nitrates, but after a while it gets saturated and just starts leaking them back into the tank. You can keep replacing it month after month, but that's money you don't really need to spend if you're staying on top of your water changes.

My canister filter came with a bag or carbon, and I used it, but then I never bought another one once that one had been in there for a while.

 

[nanu156]

carbon "works" for about 24-48 hours... then it is inert... So yeah it "helps" I guess....

Im not sure people understand what Im saying here.... YOU DON'T NEED additional filtration... There is really no benifit to pushing more water UNLESS you have a fish that needs exceptionally high current.

I am a long time fish guru and I am also strictly HOB filter. They are better, they make less mess and they agitate the surface something that a canister doesn't do....

So again, you have enough filtration, you will grow enough bacteria to eat as much poop as the fish are capable of producing if your goal is to increase bio load you need to manage nitrates higher load = higher nitrates = lots more water changes.

I don't know where everyone got the idea that you need to double or triple your filtration or that there is a benefit in it, but there is not. I repeat there is no benefit in it.

If you feel you are an advanced aquairst and you want to try to add more fish, buy a couple and test your water daily as well as monitor your fish... build up slowly... more fish = higher nitrates, there is nothing other than water changes that will drop nitrates... well there is some no change water system that adds chemicals to your water that you can try, but it's expensive and the jury is out on how well it really works.

in all honesty if you want more fish buy a bigger tank...

 

[ryanoh]

I agree, HOB are great. The reason I went with a canister is because I lost 2 HOB filters to sand and wanted something I didn't have to worry about getting ruined by sand. I have to disagree that canisters can't agitate the surface though, because my spray bar being aimed up does just fine.

 

[nanu156]

folks with cans tend to have issues with aeration.... due to the placement of the intake/output lots of times there is not enough surface agitation to get enough o2 into the water...

NOW let me quantify this with... the OP already has to HOB's and doesn't need a new filter at all, infact he is wasting some energy with the second unnecessary filter.

are there good canisters? YES thats why there is a whole group of folks who like cans, are there bad HOBs? YES, are there good hob's? yes.

My shot at cans was really due to the fact that someone tried to tell OP that he needed to add one, when he has plenty of filtration as he is, actually more than necessary (as in the second filter provides no benefit)

So since the post was about bacteria let me answer that part again, what limits the amt of bacteria you have is not the amt of surface area for them to cling to (ie sponges, gravel, filter media etc) it is actually the amt of waste your fish produce... when you have more fish you will have more waste and thus the bacteria will bloom and grow then you will have more bacteria.

The only time you need more than one HOB is when you have a rickety one that may die at any time (not the case with you) or the GPH output is too low to keep the water moving enough to not be stagnant OR enough to keep enough O2 in the water from surface agitation.

Under gravel filters are a mixed bag, I happen to like them as they keep a downward draft in the tank as well as increase current (my plecos really like fast water) They do create a mechanical filter with the gravel while providing additional places for bacteria to grow, they don't' work well with just air lines and need power heads to work effectively.

AGAIN you don't need any more filtration to increase your bio load... just do it slowly.

 

[ryanoh]

Yeah, I agree, you certainly don't need to upgrade your filters. I can see where aeration gets to be a problem with some canisters, I was just saying there are ways to figure it out.

 

[Tooj]

thanks for all the replys!
well..there was multiple reasons for me starting this tread. one was to see if i actually need the carbon in my filter, and the 2nd was to see what a filter is actually doing

um.....let me also start by saying this....i had a smaller tank before, one that had used the AC20 that i have on my 29g tank. as that filter is too small for my new tank (and it came with a topfin30 filter) im using both filters on my 29g tank. the topfin30 filter is the main filter, while the AC20 filter is being used to cycling the new tank faster.

With that said, you have cleared up some issues in regaurds to my "bioload and filtration" question. - being: nitrates are the main reason for not overstocking, and can be removed by water changes

now, let me ask you guys this:
is it safe to run only AC20 on my 29g tank IF there are no ammonia or nitrites present? or are there other reasons, beyond my knowledge, why i wouldnt want to underfilter? im asking because my topfin30 is loud as heck when im trying to sleep (its in my room..)

 

[Tooj]

there is no room in an AC filter for another sponge.
.

oh! i asked about the carbon because i was considering removing the carbon, after it had stopped working, and putting in another sponge in its place, but that doesnt seem to matter anymore =)

 

[Kitty_Kitsch]

What about tannins? Aren't active carbons useful for clearing the coloring?

 

[frankenfish]

what exactly is the isotope in our filters? is it carbon 14?

 

[ryanoh]

I've heard that undergravel filters can sometimes end up causing more bad chemicals than they alleviate because its hard to clean under them. I don't really know because I've never used one. It does seem like installing one would be a pain though if you've already got your tank running with gravel in the bottom.

What about the HOB filter is loud? If its the falling water noise you can try and fill your tank up more so that the water doesn't have to fall so far before hitting the waterline.

 

[skjl47]

Hello; I have always installed undergravel filters when setting up a tank before adding gravel. Place an UG filter in the empty tank and then add gravel on top of it. I cannot see any easy way to add one to an already set up tank.

I still do not know what is meant by problems with cleaning one. You do not have to clean them. Once in place there is no maintaince except for the tube that sticks up thru the gravel and that rarely has any issues.

I have always used air to power an UG, so cannot comment from experience about the benefits of a powerhead. It does make sense that a powerhead will generate more flow. I may try one some day. If you already have an air pump, you can avoid the cost of a powerhead. Can a power head be added to the air operated type UG filter?

 

[Tooj]

What about the HOB filter is loud? If its the falling water noise you can try and fill your tank up more so that the water doesn't have to fall so far before hitting the waterline.

its not the noise from the falling water. its the motor, or the vibration from the motor on the plastic housing (talking about the topfin30). the only noise i can compair it to is a electrical fan. it makes a type of noise as if it were pushing air around...a constant hum

 

[skjl47]

Hello; The noised you describe seems like an impeller noise. My impeller assemblies ride on a stainless steel shaft. The steel shaft is stationary. The magnet is attached to a hollow palstic tube along with the impeller.

Several problems have occured over the years that cause an impeller to make noise. Sometimes it is just a buildup of gunk on the assembly and a cleaning with an old toothbrush will take care of the sound.

I have had small snails get into the impeller area and make a noise sort of like we got when pinning a playing card to the frame of a bicycle and letting it flap in the spokes. Bits of gravel and other junk can do the same thing.

Sometimes it is the way the impeller assembly is positioned in the filter. check the little rubber pads on the end of the metal shaft. Make sure they are seated completely into the little holes in the filter housing and the siphon tube. I have had to rermove and reposition an impeller assembly several times to quiet one down.

You may need to remove the filter from the tank an clean out the hole where the impeller goes. I use some small brushes for cleaning the gunk from the inside of a siphon tube.

I have had the impeller assemblies wear enough to be noisy in operation. The early ones seemed more prone to this. I had a noisy one some years ago. I eventually pulled off the caps off the end of the steel shaft. The metal shaft was worn where the plastic tube had spun around it. The inside of the plastic tube was likely also hollowed out, but there was no way to confirm this as the wear was uniform. I eventually found a stainless rod of slightly larger diameter, routed out the end caps then glued them back on and put the impeller back in service ( I suspect that there may be stainless bicycle spokes that might work. I used a section of CB antenna.) It was more trouble than it was worth, but I could not find a replacement impeller assembly. I suspect the excess wear was partly because this HOB filter would lose suction often and run with out a steady flow of water for many hours.

Some one on this forum mentioned a HOB that does not lose prime(suction) when the power goes off. Perhaps they will list it again.

 

[skjl47]

Hello; One more thought. A hum may be in the magnetic induction assembly imbedded in the filter base. I think that the magnet on the impeller is spun by the turning on and off of magnetic fields in sequence. It could be that this magnetic induction portion of the filter is out of spec. Do not know of any way to fix that.

 

[Tooj]

thanks for the details. ill be taking apart my filter today to see if anything is out of alignment; however, some of the wearing down you mentioned may not be the problem on my filter - its only 2 weeks old!! =(

 

[1077]

Hello; I have always installed undergravel filters when setting up a tank before adding gravel. Place an UG filter in the empty tank and then add gravel on top of it. I cannot see any easy way to add one to an already set up tank.

I still do not know what is meant by problems with cleaning one. You do not have to clean them. Once in place there is no maintaince except for the tube that sticks up thru the gravel and that rarely has any issues.

I have always used air to power an UG, so cannot comment from experience about the benefits of a powerhead. It does make sense that a powerhead will generate more flow. I may try one some day. If you already have an air pump, you can avoid the cost of a powerhead. Can a power head be added to the air operated type UG filter?

I Have used powerheads capable of reverse flow to power undergravel filter's.
In reverse flow,the water is pushed down the lift tube and up through the gravel where HOB filter or canister can clean the water.
It also prevent's gunk from collecting under the filter plate and much less problems with said gunk with this type of filtration.*thumbsups

 

[1077]

Carbon does "help," but only to a certain degree. You really only "need" it to remove medicines like nanu said. It will absorb some nitrates, but after a while it gets saturated and just starts leaking them back into the tank. You can keep replacing it month after month, but that's money you don't really need to spend if you're staying on top of your water changes.

My canister filter came with a bag or carbon, and I used it, but then I never bought another one once that one had been in there for a while.

From my understanding after much research. Carbon cannot release what it has adsorbed without being subjected to extreme heat, not able to be produced in the aquarium.
Once carbon has adsorbed (as opposed to absorbed) all it can,it simply becomes another surface for bacteria to colonize.Would agreee though that it's not normally needed and thus,one can svae money to buy more fishes.