Bio-Filter Calculations

[dachmom]

My husband and I are going to add a bio-filter to our pond. We don't know how big to make it. Our pond is about 1000 gallons. Can anyone help please? Thank you

 

[Waterbug]

The calculations depend on the type of filter and the amount of food you plan to feed. Some filters, like static submerged media, can't be computed because they vary too much, the bio conversion goes down as the media is covered by sediment.

Te easiest method is to estimate just based on similar ponds, fish load, feeding, climate. And then track ammonia to see if the filter is enough. This monitoring of ammonia, nitrite, nitrate has to done in any case.

 

[sissy]

the amount of fish and the kind of fish and the size of fish .I have 2 filters one on each end of my pond and 2 pumps and 13 fish but 2 of them are over 2 feet long and i only feed them 3 or 4 times a week at the most .Also depends on how much you want to spend and what kind of filter media .I use lava rock not favored by most but it works for me .i also put lots of plants in my filters .Like waterbug says get a good test kit .At first you want to test to see if it is working alright for you .You may need to find what works for you and your pond .You tube has great video's of builds

 

[crsublette]

My husband and I are going to add a bio-filter to our pond. We don't know how big to make it. Our pond is about 1000 gallons. Can anyone help please? Thank you

There is one big point you need to accept when it comes to bio-filters if you do not want to have problems. Bio-filters do not care about the number of gallons in your pond. Bio-filters only care about the number and size of fish in the pond, how often you feed the fish, and other organics in the ponds. Most importantly, bio-filter only cares about the number and size of fish in their and how often you feed the fish.

Personally, if it were up to me, I would never buy any of the retail bio-filters unless it is for a very well built, craftsman made, shower tower bio-filter or for buying some start-up kits to put together your own bio-filter. The DIY section in this form, in the sticky threads, explains some very easy and cheap to build static submerged bio-filters.

Also, you need to think of the potential size fish will become over the years and what you will do about the fish multiplying.

So, first before anyone can help you with the bio-filter calculations, you need express how many and type of fish you are going to put in the pond, how you are building the pond, and how you are going to manage the pond. Just a very quick, concise summary; the summary doesn't need to be too long, just enough to give us a snapshot idea of what you want to do.

 

[sissy]

true I started with one filter but now I have 2 as of 3 years ago .Now I will be changing out the round tank for an oval one so I can put more plants in it .

 

[dachmom]

Thanks for the info everyone, the pond is 2 yrs old. We have about 20 fish, 4 koi and the rest are goldfish. I know that is too many but will be giving some away to my brother when he builds his this summer. We were thinking about using scrubbies and some other material. My husband wants to make it out of stainless steel (he works at a fab shop) and then he will put a liner in it.

We like to feed the fish every day, Hope this helps

 

[sissy]

if water gets between the stainless steel and the liner it may float the liner up .Above ground or below ground .Make your filter a stainless steel would be ok and modern looking

 

[Waterbug]

OK, so the calculation between scrubbies (static submerged media) and something like a Trickle Tower filter would be roughly 30 to 1 based on tests for ammonia conversion. Meaning you need 30 times more scrubby volume compared to Trickle Tower volume. The scrubby filter has to be 30 times as large to convert the same amount of waste. And you'd still have to keep the scrubbies clean or it gets even worst. Cleaning scrubbies is a lot more work compared to something like a Trickle Tower which cleans itself.

The other part of the calculation, filtering need, can be estimate because this is an existing pond. I assume ammonia has been low because the fish have survived 2 years so far. So currently the pond needs no additional bio filtering. That means the scrubbies would be fine because they aren't actually needed. Going forward that could change depending on fish load.

 

[crsublette]

I think Waterbug's point is...

Dachmom, do you want your husband to build a bio-filter that will last you for the short term or a bio-filter that will last you for the long term ?? You would want to build one that will last you for the long term since it would cost you less stress of worry and less money in the long run; this is why folk typically build their bio-filtration system to be quite oversized. With your husbands skills along with your input, he can build quite a dandy.

Short answer...

I would have him build something like the shower tower hyperlink posted above and then simply have the foam pads or lava rock in the container. Then, have him build some type of dispersal plate on top so to only shower or trickle the incoming water on top of the material and then let the water exit out of the bottom. This type of filter is called a wet/dry filter and they are extremely efficient bio-filters while maintaining a very small area footprint.

Quick side note.... for your bio-filtration to work better, you need the pond water to be mechanically filtered. A "Mechanical filter" is simply seperating the large water debris and very small floating debris before it enters your bio-filters. If this debris is allowed to enter your bio-filter, then it will reduce your bio-filters performance and you will have to flush out the bio-filter container more often.

 

[crsublette]

Long answer...

I hope this long answer gives you an idea of why it is tough matching a bio-filter to a person's pond and why a pond's fish stock density determines the bio-filtration. Also, fish will reproduce and this will stress the filtration as well.

Also, keep in mind, inserting floating pond plants and pond plants in pots with a mixture of laterite and crushed coral or lithaqua or other stuff will add to the bio-filtration system of your pond.

Quick side note. Talking filtration in the pond hobby can be exactly like talking politics. So, to help you sift through all of the personal beliefs, facts, opinions, experiences, and advice, you need to answer a few questions. How much of an area footprint do you want your filtration to occupy?? How much do you want to spend?? Does aesthetics or noise matter or will the filtration be in a pit or in a storage shed?? What do you feel comfortable doing including additional construction or material hauling or extra digging ??


This approach is based on how I approach pretty much everything in life. "Plan for the worst. Hope for the best."

I use a couple of generallities in determining when bio-filtration is needed like on a scale from 0 to 4. .5 meaning you don't need anything. 2 meaning you need bio-filtration. 4 or more meaning you really really really need a bigger and more efficient bio-filtration system.

Now to apply this scale to your situation, think of the fish's potential size. "Potential" is defined as "capable of but may not be". Ultimately, fish genes, water chemistry and water quality, ecosystem health, food quality, attention to detail to maintenance and equipment, water exchange, and food regiment will determine if the fish will reach its maximum potential size. Eventhough it may be unlikely your fish will reach the maximum potential size, I think it is better safe to assume the fish will obtain their maximum potential size.

The maximum potential size of a comet goldfish is around 14" (give or take a couple inches), but lets use 14" so to lean on the side of preparedness, that is "planning for the worst".

Maximum potential size of koi is around 32" (give or take a couple inches), but lets use 32" so to lean on the side of preparedness, that is "planning for the worst". Since koi become bigger and can digest higher quality food, they can possibly produce 2 times more waste than comet goldfish.

Thanks for the info everyone, the pond is 2 yrs old. We have about 20 fish, 4 koi and the rest are goldfish. I know that is too many but will be giving some away to my brother when he builds his this summer. We were thinking about using scrubbies and some other material. My husband wants to make it out of stainless steel (he works at a fab shop) and then he will put a liner in it.

Ok. For example, your pond is 1000 gallons. 4 koi (4*32*2= 256). 16 comet goldfish (16*14= 224 inches). Total the results and multiply it by 10 and then divide the result by your pond's gallons. This gives me a scale ratio of 4.8. So according to my scale reasoning, your fish load in your pond will potentially, possibly after a period of months or years, require a much bigger and/or more efficiently built bio-filter.

Food quality and feeding regiment will tremendously obscure this scale as well. Unfortunately, I have not yet found a way to quantify the food's effects to bio-filtration on a simple scale example. Essentially, increased feeding regiments and higher food quality will stress the bio-filtration.

Ultimately, a good way to know if your bio-filtration is failing you is by testing the Total Ammonia and Nitrite levels in the pond. During the summer season, if these levels increase above 0 and stay their longer than 24 hours, then your bio-filtration unit is failing. It might be failing due to gunk and debris accumulating in the unit, slow water flow through the unit, not enough material in the unit, unit is too small, or unit is not built well.


Personally, I believe and, according to the literature and experiences I have read, the wet/dry filters (as I described in my previous post), shower towers, trickle towers, and fluid or moving bed filter are extremely efficient bio-filters.

 

[dachmom]

Thank you everyone, alot of great ideas and suggestions. I think my husband and I have more research to do. We plan on going shopping this weekend.

 

[sissy]

check out you tube to see some builds there there is tons to look at .

 

[Waterbug]

I think Waterbug's point is...

I think crsublette's point is he would like to speak for me. What he doesn't understand is that I can speak for myself.

What I think Waterbug's point is, and I consider myself somewhat of an expert on what Waterbug thinks, is exactly what Waterbug wrote. Further more, Waterbug thinks Dachmom is smart enough to read Waterbug's post and use that info how Dachmom see's fit. Waterbug also thinks that if Dachmom has any questions about Waterbug's post that Dachmom is able to type that question into a post. Waterbug believes this to be true because Dachmom has formed posts in the past and therefore assumes Dachmom is still capable of typing.

You see, that's kind of the point of writing posts, to express a view point. While the world will always be full of people with huge egos I think it really gets a bit silly when they actually start believing themselves to be so omnipotent that they can read other people's minds and feel it is their duty to speak for people who are obviously unable to voice their own opinion.

 

[sissy]

well at least you are doing lots of research and better than what I did .I just jumped in the deep end and guess i was truly lucky .I think my background helped also since my dad had an organic farm and a pond and natural stream on the property .no fancy fish of course .I wish I had heard of this forum 9 years ago and heard of you tube also .Really helps to see people truly building stuff .

 

[crsublette]

Waterbug, I'm not speaking for you nor making an assumption of the author, I'm just playing with ya. I kind of thought that would rile ya up a bit. I :luxlove: ya man. :bdaybiggrin: