Is A Tanks Bio-load Capacity Related To Overall Surface Area?

According to aquarium advisor, my current "filtration" capacity is around 110% at a 70% stocking level (recalling from memory). I understandmakes conservative estimates, but I do want to be somewhat safe about it. I am currently happy with my stock as they will need to grow out (juvinals). Just asking this question for the future if I do decide to add more fish.

Current filter is a canister Eheim 350 Pro 4 (rated at 277GPH full throttle according to website), so that's about a 3.6x Turnover per hour.

Is biological filtration capacity largely related to surface area? 3 of the media baskets in my eheim I would say are only 3/4 of the way full. So I could add roughly 25% more media to each basket. Would adding/filling the baskets with more "surface area" allow me to accomodate a larger bioload if all other things are equal? The second basket after mechanical (mix of Eheim MechPro and sponges), is BioMech which ive read has FAR less surface area than the final basket (substrat pro). If I was to replace the 2nd basket with substrat pro and fill out the baskets with the proper media, would this give me more headroom for future fish expansion to my 75Gals stocking capacity? (Rememberis currently saying my filter is at capacity at ~70% tank stocking level).

Tank Info
6x Boes Rainbows
12x Tiger barbs
1x BN Plec
1x Rainbow Shark

about 8 vals scattered around the tank, 2 large anubias, ~6 javaferns with driftwood.

 

The simple answer is yes, increasing your surface area increases your filtration capability

 

Yes because it gives more surface area for bacteria to colonize on. More bacteria can handle more ammonia caused by heavier stocking.

However filtration capacity is not a massive part of stocking. IMO the most important thing concerning stocking levels is how much space the fish have.

 

AQAdvisor also bases stocking level on the footprint of the tank. So if it is 70% stocked for a 20 L, it will also be 70% stocked for a 29 and 37 gallon as well. Your filtration won't have an impact on that number they are providing. If you take out your filter, you will get the same % stocked number from that site.

 

AQAdvisor also bases stocking level on the footprint of the tank. So if it is 70% stocked for a 20 L, it will also be 70% stocked for a 29 and 37 gallon as well. Your filtration won't have an impact on that number they are providing. If you take out your filter, you will get the same % stocked number from that site.

That is great to know, I never actually played with other tank dimensions either. With my 75Gal 4ft long tank @ 70% stocking as it is right now, I was just concerned with its recommendation to "increase filtration capacity" If I even added another tiger barb. I was unsure if that litterally meant get another filter, or if my current filter could be "more efficient" given the GPH stayed the same. Just wanted to know if I made my 1 single canister "better" could I safely hit a 100% stocking level.

 

Keep in mind that there's an inverse relationship between filtration capacity and stocking level. Stocking level above 100% is bad (all else being equal) because it implies that you have more fish than your tank is capable of supporting. Filtration capacity above 100% is good because (all else being equal) it implies that your filters are capable of handling more waste than your fish produce.

 

I understand. Currently this is whatis giving me:
Your aquarium filtration capacity for above selected species is 104%.
Recommended water change schedule: 22% per week.
Your aquarium stocking level is 73%

If I added lets say 8 more tiger barbs from this existing level I get

Your aquarium filtration capacity for above selected species is 84%.
Recommended water change schedule: 28% per week.
Your aquarium stocking level is 86%.

Which is what drove me to ask this question in the first place. Would this be a matter of simply adding more effective Biological media if all other things are equal (since my canister has the room for it. 277GPH in 75Gal)?

Or should I "heed" its warning and eventually add another filter. BTW I do a 25-30% weekly PWC without fail.

 

That is great to know, I never actually played with other tank dimensions either. With my 75Gal 4ft long tank @ 70% stocking as it is right now, I was just concerned with its recommendation to "increase filtration capacity" If I even added another tiger barb. I was unsure if that litterally meant get another filter, or if my current filter could be "more efficient" given the GPH stayed the same. Just wanted to know if I made my 1 single canister "better" could I safely hit a 100% stocking level.

If you go over the filtration capacity but there is still plenty if room in your tank for fish you can still add more fish if you do extra water changes. However this doesn't work if you have fish that are territorial for example as they need more physical space in the tank.

 

Which is what drove me to ask this question in the first place. Would this be a matter of simply adding more effective Biological media if all other things are equal (since my canister has the room for it. 277GPH in 75Gal)?

That's a good question. Whenmakes its calculations, I don't know whether the "capacity" for a given filter is based on its media volume, flow rate, some combination of the two, or something else. A good test would be to compare filtration capacity for the same fish with two filters that have the same GPH but different media volume, or vice versa to see how the percentage changes (or doesn't). I'm not familiar enough with different brands/models of filters to know where to start with that, though (I'm a noob).

 

That is what is driving me crazy aboutat the moment. Everywhere I read its either "flow flow flow" or "BB BB BB", or Both turn over + media volume. Logic is telling me More BB = More fish. But as I found in this hobby nothing is clear cut, so I was hoping someone could shed some light on this.

 

That is what is driving me crazy aboutat the moment. Everywhere I read its either "flow flow flow" or "BB BB BB", or Both turn over + media volume. Logic is telling me More BB = More fish. But as I found in this hobby nothing is clear cut, so I was hoping someone could shed some light on this.

I noticed that if you click on the little question mark next to the filter selection section on AqAdvisor, you can find the following paragraph in the site's help page:

"The simplest way to use this feature is to select one of the pre-defined filters. Most of the well-known filters should be on the list already but if it isn't there, you can leave a feedback in the forum. If it makes sense, they too, will be included in the list. If your filter is not defined as one of the pre-defined filters, then you can select 'User Defined' item. This will allow you to specify the aquarium filter capacity yourself, which means you can easily abuse it as well. The capacity is measured in US Gallons(gUS) by default. If you are displaying in Litres(L), then you must specify the capacity in Litres. Note that the application requires the filtration capacity, not flow rate (see below)."

The next paragraph of this section discusses how manufacturers have different approaches to calculating their capacity, some relying more on flow rate and others relying more on efficiency of the filter media. The later section defining "filtration capacity" essentially says that the site uses the "actual filtration capacity" of the listed filters, which is somehow assumed to be 65% of the manufacturer's rated capacity. What seems clear, at a minimum, is that filtration capacity is not based solely on flow rate. It seems to be some combination of flow rate and media type/capacity, which varies from filter to filter.

 

That is what is driving me crazy aboutat the moment. Everywhere I read its either "flow flow flow" or "BB BB BB", or Both turn over + media volume. Logic is telling me More BB = More fish. But as I found in this hobby nothing is clear cut, so I was hoping someone could shed some light on this.

Your surface area and there by your BB capability is paramount. The flow rate plays in with your circulation ratio. Theres a lot of opinions on what is good what is bad. Realistically you want a current in your tank so that the in tank circulation is happening. This then helps the filter since you have fluid mixing in the tank better and the filter is effectively moving water around more efficiently. This is accomplished with the intake and outlet on opposite sides of the tank. Now is 10x per hour required? No I don't think so not at all. That being said my 125 gallon tanks are running sumps that are 800 gal per hour and my 350 and 550 are running 1500 GPh on their sumps. My water chemistry is excellent and my cichlids all spawn regularly.

 

That is great to know, I never actually played with other tank dimensions either. With my 75Gal 4ft long tank @ 70% stocking as it is right now, I was just concerned with its recommendation to "increase filtration capacity" If I even added another tiger barb. I was unsure if that literally meant get another filter, or if my current filter could be "more efficient" given the GPH stayed the same.

I think they base the filtration on what the filter is rated for. Like your filter I think is rated for "Up to 92 Gallons".
So like your tank with the stock listed would be:

Your aquarium filtration capacity for above selected species is 104%.
Recommended water change schedule: 22% per week.
Your aquarium stocking level is 73%.

If you added a AquaClear 110 in addition to your canister as an example it would be:

Your aquarium filtration capacity for above selected species is 230%.
Recommended water change schedule: 22% per week.
Your aquarium stocking level is 73%

You can't stock more fish, but you can handle a larger bio-load.

They have a link under "beginner articles" "How does aqadvisor work?" you might get a better idea of what it is doing behind the scenes.

I would say if you are under 100% then it is a good idea to get a second filter or stock less. There are a lot of factors like ACTUAL flow rate, surface area for BB, plants, water changes, etc...You can get close, but those other factors come into play and you just have to make sure with your water tests, that everything is going well.

I happen the like the site, some people hate it. I take it for what it is, a nice tool to help get a general idea on stocking my tank.

 

So the bottom line is if with my current filter set up, even if I added more biological media to the canister assuming its flow rate "stays the same", I'd still have to experiment with its upward ability to consume the ammonia/nitrite in the tank, which as you stated would vary on plant load etc.

So my tank could hold 29~% more fish for just simply the container but at AqAdvisors stats my filter is at capacity. So I would be wading into unknown territory essentially if I didnt add another filter.

The bottom line is water quality, which would mean, 0 ammonia/nitrite at any random sample, Nitrate ~<30ppm at a given water change interval, and water "clarity".

So I would have to just experiment. Am I correct with what the definition of "water quality" is?

Also just clarify, I don't intend to hit a 100% stocking level, I was planning on the possible addition of a few more barbs and maybe 1 more rainbow fish in the future, which would still leave me under 100% stocking.