# Plant filtration



## AndyL (Jun 5, 2004)

Hey folks,

I just started the process of doing a complete overhaul of my fishroom (and adding 6 40g breeder tanks) To keep the wife from killing me when she sees the water bill, I'm looking for some ways to save on that darn water bill... 

I've heard of people using 'plant filtration' to help maintain water quality (suck up the NO3 / PO4) to reduce water change needs, but I have yet to see one of these systems - anyone have some advice on plants to use, overall design? 

Andy


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## plantbrain (Jan 23, 2004)

Plant filters have been around since the 1800's.
How these will fit your needs is another question. High PO4 will not cause issues for Discus, that is one of the anions they use for Discus buffers etc.

NO3/NH4 are another issue. 

Discus are often over feed to achieve larger sizes which "more is better" in their view. All this food causes lots of waste. 

You can get rid of the waste by exporting it as plant cuttings. Emergent plants are best for filtering applications, they need less light, no CO2 and are easier to place in a system.

Basically a large sump with hydroponics media can be used and adapted for plant growth. You will need a light to grow the plants, but a shop light would do fine. 

A well set up system can go 2 years or more without a water change and have the Discus breed.
But you are not going to maximize your brood unless you stick with the basic water changes in barebottom tanks etc.

There will be a trade off. Things will slow down and no water changes will not allow for so much feeding etc.

But it will help a lot and may even reduce the water changes down to 50%-75% or more.

Peace lilies work very well.

As far as a plant to add to the tanks: water sprite works very well.

Regards, 
Tom Barr


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## AndyL (Jun 5, 2004)

Not sure if breeding discus is in the works for me yet... I'm more focusing on Angels, rams and maybe some other dwarf cichlids. The angels definitely follow the same process as discus, they are fed heavily on beefheart to put on size rapidly...

My plan so far, had been to keep the basic overflow & sump setup I've got working now, but to add duckweed to the section containing the primary heaters (there are secondary heaters in the tanks), then screen off the output of that section so the duckweed doesn't end up clogging the pump / drip emmiters. And of course add some light (24" shoplight would fit nicely)

What about algae? Could I 'cultivate' some algae (whatever type, hair came to mind) in the sump to suck up the excess nutrients? Would require the addition of a UV filter to prevent spreading through the tanks, but it seems like it could be workeable too. 

I don't think I'd trust eliminating water changes for even a month - I tend to follow the belief that fish need fresh water, while they grow they definitely are using up nutrients from the water, and those need to be replaced...

Andy


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## plantbrain (Jan 23, 2004)

I've had tanks that have no water changes for 6 months or longer with plants. Fish bred.

As far algae or duckweed, don't waste your time. These are no where as effective at high load rates for nutirent removal and both are messy and hard to deal with in the main tanks. They also require far more light for the same amount of uptake.

Emergent plants are far more efficent at reduced light(thus electrical cost) and also in terms of dry biomass export. Algae is 95% water, emergent plants are 80% or less. 

They also do not get into your tanks..............

As far as using a UV to prevent algae, no, that generally will not work, it'll keep things reduced, but a few will make it through or go airborn and make into the tank.

You can use PCV 3" tubes with peace lilies in them and test caps glued to the bottom and filled with Profile(or better yet, hydroponic media, the clay porous balls, they will not clog as easily) etc and trickle water through these slowly.

Cut the PVC to 2x the average height in the sump, fill with profile/Hydro media, drill many small 1/8" or so on the bottom 1-2".

This way you can add as many "pots" of whatever plant you wish to grow in there and remove them for trimming, cleaning etc.

Very cheap, simple and practical over the long term.
2x20 w of light is plenty for 10 or so of these tubes. 

Regards, 
Tom Barr


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