HOW TO MAKE A NO WATER CHANGE AQUARIUM WITH DO-IT-YOURSELF HYDROPONIC/AQUAPONIC FILTRATION SYSTEM

How I built a DIY no water change hydroponic/aquaponic filtration system for an existing 46 gallon freshwater aquarium to replace a conventional canister filter with biological media. Nitrate, nitrite and ammonia test results show as low as 0 PPM over a year without a single water change. The mostly native American wild caught fish and plants are thriving.

The hydroponic aquarium filtration system was set up in September 2020 and the canister filter was removed in November 2020.

From November 2020 to February 2022--- NO WATER CHANGES WERE MADE.

Nitrate readings were between 0 and 20 PPM for the first few months. After this period nitrate readings varied, mostly in the lower half of this range, mostly 0 - 5 PPM. Readings were conducted with both API brand reagents and test strips.

I assume the nitrate readings gradually reduced as the root systems developed.

The 46 gallon tank was taken down on February 8, 2022, and a new 75 gallon setup was completed on March 22, 2022. Fish from the 46 gallon tank, which had been housed temporarily in a 20 gallon, were introduced into the 75 gallon the same day.

The same hydroponic filtration system was activated for the 75 gallon tank with exception of an additional pump; the system now has two Cobalt Aquatics E-X-T 800 inline pumps.

The water test results on the 75 gallon so far:

April 29, 2022--- API Test Strip--- 0 PPM Nitrates & Nitrates

May 9, 2022--- API Reagent--- 5.0 PPM Nitrates
API Test Strip--- 0 PPM Nitrates & Nitrites

June 2, 2022---API Test Strip--- 0 PPM Nitrates & Nitrites

I have experimented with plant filtration for a few years and watched many, many videos on the subject on Youtube. The biggest take away is that two or three pothos stems in a hangover-the-back filter, as seen in countless Youtube posts, will not be sufficient to maintain a no-water-change aquarium.

DEPLETION OF TRACE ELEMENTS:

One concern regarding no-water-change aquariums expressed by hobbyists on YouTube is the depletion of trace elements required by fish and plants.

I am not a scientist, so I really don't know. However, I have not noticed any new problems which I did not experience in tanks with water changes.

My tanks experience more evaporation than average as they are outdoors in the hot Florida climate. Plus, there is additional loss of moisture through the leaves of the hydroponic plants.

An automatic top-off (ATO) system with a 30 gallon reservoir for this 46 gallon and a 20 gallon tank lasts 24 days. This rate is equivalent to a 45% water change every 24 days. With the 75 gallon and 20 it is 31% change every 24 days.

Hopefully, this is sufficient to address any trace element issues.

Of course, you can always add trace elements if you have a concern.

PARTS USED:

GROW TRAY is a Home Depot concrete mixing tub ($16.27). A lot cheaper than a true hydroponic grow tray in the $80 range. https://www.homedepot.com/p/Plasgad-Black-Large-Concrete-Mixing-Tub-887102C/205451585

1/2 INCH CPVC PIPE--- https://www.homedepot.com/p/Charlotte-Pipe-1-2-in-x-10-ft-CPVC-SDR11-Flow-Guard-Gold-Pipe-CTS-12005-0600/100170202

VALVES--- https://www.homedepot.com/p/1-2-in-x-1-2-in-Slip-x-Slip-CPVC-Solvent-Weld-Ball-Valve-107-123HN/100347099#overlay

PLASTIC GRID PLANT PLATFORM--- The grid in the video comes with an air-conditioning filter we use at home which can be easily cut to size. You can also use the "egg crate" which is used by so many aquarium hobbyists for many things; or a conventional hydroponic platform for potted plants (if there is one that fits the cement mixing tub). However, the last one is expensive and requires more work--- individually potting each plant--- and will not fit as many plants as a grid.
https://www.homedepot.com/p/Web-20-x-25-x-1-Absorber-Odor-Control-FPR-5-Air-Filter-WABSORBFPR/100011568

GROW LIGHTS
https://www.amazon.com/gp/product/B0814L4XPL/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&th=1

GROW LIGHTS FRAME---Black PVC pipe and elbows
https://www.homedepot.com/p/Formufit-1-2-in-Furniture-Grade-PVC-3-Way-Elbow-in-Black-10-Pack-F0123WE-BK-10/205749368
https://www.homedepot.com/p/Formufit-1-2-in-x-5-ft-Black-Furniture-Grade-Schedule-40-PVC-Pipe-2-Pack-P012FGP-BK-5x2/312192322