Lava Rock Fountains

Lava Rock in the pond? After all I've said on the subject? Well, this is one place that I'd have to make an exception to my "No Rocks Rule." This DIY project was sent in by Griff Thomasson. He has done some *very* nice work with the Lava Rock Fountain! Griff and I have a different approach to Trickle Towers, but I've said my piece on the subject on another DIY page. What Griff and I *do* agree on is that a TT *will* benefit most any pond. How you go about it is subject to much discussion, but the important thing is that you should be aware of this type of filter and what it can do for your pond.

I have said that the Lava Rock Fountain can be considered a decorative water feature. These built by Griff illustrate that notion. I think the man's an Artist!

Enough of my ramblings. Over to Griff!

(With Special Thanks to Roddy Conrad and to Larry Wolmack !!!!!)

Last year I built a 5500 gal pond. Did not know what I wanted . At first it was to be a water garden. My wife and I realized very quick that we sat out by the pond to watch fish and not plants!!!!!!!!

THE KOI BUG BIT US!

I had a nitrite spike last August from a submerged filter just finishing up It's cycle. So I hit the Internet looking for ways to improve bio filtration?? I started reading all the good stuff about Trickle tower bio filters. I have been burned by the sales pitches on several pond products and was very skeptical!! I saw the lava rock fountain that Roddy Conrad uses from Nevada Water gardens and said heck I can build that!!! Roddy was not selling anything he just talked about how good a job they did for him.

Out came the card table and hot glue gun. I went to the local Lowes store and bought 4 bags of Lava Rock. ( It is really clinkers from a steel mill) I glued up this fountain. It is just a basket with a pipe up through the center. Filled with lava rock after it was placed into pond. Pump is a Rio 2100 placed under fountain. Fountain rests on several pieces of flue pipe. Fountain size is 18"x18"x24"

This fountain gave me across the board perfect water quality. Nitrates dropped from 15PPM to less than a .25PPM. This fountain cost me $34.00 to build not counting the pump. I was very impressed with it's performance!!! I un-plugged my UV light. I have had clear water every since. Fountain was installed in August of last year and the only maintenance has been to clean off the algae growth on top of fountain only once!!!

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Last winter I built 6 more fountains using lava rock as media in each one and using several different designs and set up tanks and tested how they worked. All set-ups were virgin. I came to a few general conclusions, The larger they are, the easier to cycle. Cycle time was 3 weeks in all cases. 4 days with seeded media from out side fountain. Work much better if they are at least 18" high. Smaller fountains less than 3 cu ft of media will take a low flow rate to cycle but once cycled will take a higher flow rate. Small fountain rule of thumb!!!!!!!!! 50 gal per hour per cu ft of media. Trickle towers require some type of trace minerals for them to cycle. Perform better with high KH values. 190-250PPM range If flow is too high nitrates will form and so will nitrites, This makes sense. Is flow is too high media acts as submerged media.

Fountain #2 was built as my fish load has increased and I am reaching the bio capacity of the first fountain. I wanted a set up that would pass my entire pond volume through a TT every hour or so. I also have submerged filtration. This fountain is a big improvement over the first, in that I am using natural volcanic black lava rock. Why does that make a difference? Well black lava has a high balsite content and will leach out trace minerals for years. Feather rock was used to form the basket. It is natures bio glass.

Click on the images for larger version and more text.

The first attempt. I built this with the hot glue and a epoxy glue to reinforce the hot glue but the hydraulic pressure blew out the from of the fountain. I cleaned everything up. ( the glue held the rock broke) Feather rock is very soft and can be split with a axe just like wood. Wear gloves as it will cut you!!!!! The finished fountain was built in place using a hydraulic mortar. I used "sakcrette" and added a shovel full of type s hydraulic mortar to the mix. Fountain was placed in an upper veggie pool on the out flow from submerged filter box. 3000 gph. Fountain was built on 3 pieces of flue pipe spaced out to give a 34"x24" base. Flat stones were place over the spaces to build fountain on top. Flat stones were also used to allow water to flow out bottom but not to let lava rock fall through spaces in-between flue pipe. Construction time was 3 hours including clean up of mortar joints. I let it cure for a day or so and valved it in. I have 10 bags of natural lava rock in this fountain and 5 cu ft of feather rock. Lava rock has 350 sq ft of surface area per cu ft of media and feather rock has (best information source) 7000 sq ft of surface area per cu ft of media. I have 38000 sq ft of surface area in this fountain for bio activity.

I checked PH every day to make sure that I did not have a pH run up and after a week not increase has been noted. Nitrate levels have dropped from 4 PPM to 0 on 5 days!!!! Nitrate levels checked with a Lamotte test kit. Total cost of this fountain is less then $125.00, 4 hours work!!!!

I do not care how you build a TT or what kind of media you use JUST BUILD ONE YOUR FISH WILL LOVE IT.

My goal is that my fish out live me and are a pain in the butt for my kids!!!!

ADVANTAGES OF TRICKLE TOWER FILTERS

1- Much faster to cycle 4 to 21 days as compared to 60 days for a submerged filter.

2- A factor of 50 higher for nitrite conversion than a submerged filter.

3- A factor of 1000 times greater for low nitrates as compared with a submerges filter. ( If properly built no nitrates will form.)

4- A trickle tower adds oxygen to the water where a submerged filter removes oxygen.

5- Lower water temps in the hot summer due to the evaporative cooling of a TT.

6- Lower DOC content in a pond running a TT.

7- Fish have better color due to lower nitrites and lower nitrates and lower DOC.

8- Usually will control green water with out a UV light.

9- Running a TT and a submerged system gives the best of both.

10- No poor water quality in the spring while waiting for submerged to cycle again.

11- Will handle high fish loads. (Like Mike said, we never do that)

12- Low maintenance!

13- Very cost effective!

DISADVANTAGES OF TRICKLE TOWER FILTERS

1- Must be above pond surface for gravity return to pond. They are hard to hide.

Griff Thommasson

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