Backyard Aquaponics
A place to discuss aquaponics

Just saw in the BYAP System Installs Ray's System which, as most BYAP installs do, looks great. Faye says that the existing bio filter was disconnected and I want to ask the forum, if you had a similar existing large koi pond why not simply leave the bio filter in place?

My thoughts on the pond-filter-included thing is that if you are looking after fish then filtering of the water is top priority. Those bio filters provide an adequate home for the nitrifying bacteria without any growbeds attached. The growbeds can then be thought of as simply a plant holder, providing something in which the plants grow, with scant regard for their filtering abilities. It, in theory, means you can take growbeds offline, wash them, etc with far less impact on the engine room of the system - the fish.

One glance at this forum and it's obvious that systems function just fine without a pond bio filter but if you already have one why not use it? Would love to hear other points of view.

Thanks in advance,
Pete

It's quite possible that the filter may merely be de-activated, rather than totally removed Pete... and indeed I'd probably do so... just in case it was ever needed...

But in reality... growbeds perform not only the necessary bio-filtration... but solids capture/breakdown...

And with the addition of worms... rarely require maintenance such as cleaning ... or "washing down"...

My pond has a small barrel swirl solids capture filter then a trickle filter. I only ever clean the trickle filter every 6months so its fairly maintenance free. (60 mins dipping the sponges in a 55L bucket)
The swirl filter is now dumped into my new duckweed tank weekly instead of around trees.
I do monitor for ammonia etc with no traces.

Since its takes about 6-8 weeks for the biofilter to kick in properly de-activating it does not make sense to me.
Once I get the growbeds online I will probably reduce it to a smaller flow pump but I look at the biofilter as a safety net.

I do know of one situation where it might be a good idea to do away with a bio-filter. If it is one of those types of filters that needs a certain amount of pressure to make it function properly. There is no need to use that much electricity to run an aquaponics system and having to pressurize a sand filter would require more electricity than is really called for.
We have finally disconnected the sand filter that has been tied into my big system for ages (really wasn't doing much but I usually kept a trickle of water going through it so it wouldn't go anaerobic on me and that is the reason that I wouldn't leave something like a sand filter sitting there just in case you needed to tie it back in, ya leave one of those sitting for three days with no flow through it and then turn the flow through it back on and your nose is going to tell a story of hydrogen sulfide. Let me tell you, if your system is having water quality issues and spikes and you need to add extra filtration fast it protect fish health, opening up a valve to something that is going to provide hydrogen sulfide is not the best choice for protecting your fish health.

Also, any bio-filters that need regular attention might be worth selling off if you are trying to reduce your personal labor in maintaining a system. If you don't mind the extra stuff, then by all means keep it online though anything that removes solids also removes extra nutrients from your system. If your main goal is lots of fish, this could be a good thing but if you want to grow lots of fruiting veggies, then you should probably get a good portion of the solids up into your grow beds.

As to pouring the cleanings from a swirl filter into a duckweed pond? Is this duckweed pond sharing circulation with a fish system? If it is, be careful of the gunk in the bottom of a duckweed pond. If it goes anaerobic, you can get quite the pockets that if disturbed in any way can give off hydrogen sulfide and that is not good for fish (or m gag reflex.) This was my biggest issue with the duckweed pond, since duckweed likes fairly still water anything falling into the pond tends to settle to the bottom and it can easily become anaerobic, then any disturbance to the water can cause huge issues.