Designing a 50 Gallon System

[Justin]

I am new to this and have been researching and starting to piece together a 50 gallon system. I live in NH and will be putting this system in my basement. I recently bought a very cheap 50 gallon aquarium on craigslist and have a pump on the way. I am still not 100% certain what type of system I would like to create. I have several questions listed below. Sorry to bombard everyone with questions my first post.

 

1. I have read conflisting information stating that this is basically the minimum size required to raise tilapia (50 gallons). I understand it is much harder to use a small tank than a large tank but is this truely possible? I would be thinking about a stocking density of 5-10 fish. (1 fish for every 5-10 gallons)  What other edible fish could be raised in such a small system? I plan on using gold fish to cycle the system but am thinking my long term plans are something tasty.

 

2. I understand that I need at least a 1:1 GB to FT ratio. If I have 50 gallons of grow bed and use a normal flood and drain system, where the pump is in the fish tank and delivers water to the GB above it, how much will my water level go down in my FT? I understand the grow bed is full of grow medium, but it still seems like it will lower >20%. When determining stocking densities should I be looking at its lowest point or just the nominal 50 gallons of the tank.

 

3. To avoid the tank draining issue in #2 I have thought about adding a sump tank. Can you safely drill a hole in a glass aquarium to add a drain pipe on the side? I am looking to keep the water level constant and as high as I can. Is there any other way to do this?

 

4. My other thought for solving the draining issue was to have several small grow beds and an indexing valve. I have read that these require intermittent flow. I have also read that a pump will die much sooner if it cycles on and off rather than runs constantly. How much life should I expect out of an intermittent run pump? Is this something I should not worry about?

 

 

[Chi Ma]

For this size system you will definitely want to run a sump and have constant water height in your fish tank. If you don't your 50 gallon decreases by however much your grow bed holds.

Check this link out.

http://practicalaquaponics.com/blog/?p=219

[TCLynx]

1-some people think goldfish are plenty tasty (they are just fancy carp) though they have lots of bones which puts off most Americans.

2-Water level fluctuation could be as much as 40% though usually a bit less.

3-Yes, an aquarium can be drilled, they make special hole saws for drilling glass.  There are things called no holes overflows but they can be prone to failure.

4-I doubt you would want to run a big enough pump to operate a normal Indexing valve.  I run my indexing valves with mag drive pumps and I'm known to turn the pump on/off 6 times per hour 24/7.  The pump in my 300 gallon system is still working and it's been doing the job for over a year and a half.  But the indexing valves (even the gravity modified variety) still require a certain amount of flow/pressure to operate and the smallest pump I've managed to operate the gravity modified version with is almost a 1000 gph.  Now if you are mechanically inclined, Rob Torcellini released a video showing the construction of his small motorized sequencing valve which would work with the flow from a small pump and would not require turning the pump on/off.  But you would have to manufacture it yourself.

[Justin]

Thanks for the responses. TCLyncx, my girlfriend already thinks I'm crazy for thinking of growing fish and vegtables in the basement. I think eating gold fish would put her over the edge! It sounds like a sump and constant water height is my best choice. I really didn't want to have to cut the aquarium.

 

With the sump should I be fine for tilapia? Are there any other typically eaten fish that would work in such a system?

[TCLynx]

Doing this indoors, Tilapia are probably you best choice for a small tank.  (Indoors you can keep the water warm enough for them easier.)  I would recommend getting a dehumidifier for the basement since you are likely to see some humidity issues with warm water and cold walls.

You might be able to find an aquarium shop or some one with experience that might be willing to cut the hole for you.

Go for it and Be CRAZY!!!!!  It is really a great feeling to eat food you grow yourself, eventually you will win the girlfriend over to it.

[Averan]

in order to achieve a constant height in the fish tank, overflowing into the sump, you MUST cut a hole in it.  either that or let the water fill up and spill out everywhere....not exactly desirable in any situation.  order yourself a cheap glass hole saw and drill baby drill!  it takes a while, but is well worth the effort.

i've got a 55 gallon tank with 8 koi overflowing to a 30 gallon sump powering a 50 gallon grow bed along with about 25ft of NFT pipe.

have you filled up your tank to check for leaks?  the hardest part of setting up my system was rebuilding the 55 gallon aquarium i got for free!  often times there's a very good reason the tank is free.  ;)

[Justin]

Did you use a pvc bulkhead fitting on the aquarium? Did you pipe it from the hole at the top to the FT bottom for solids pick up? What diameter would you recomend? I was thinking 3/4" or 1". Looks like I will be running to the hardware store today!

 Averan said:

in order to achieve a constant height in the fish tank, overflowing into the sump, you MUST cut a hole in it.  either that or let the water fill up and spill out everywhere....not exactly desirable in any situation.  order yourself a cheap glass hole saw and drill baby drill!  it takes a while, but is well worth the effort.

i've got a 55 gallon tank with 8 koi overflowing to a 30 gallon sump powering a 50 gallon grow bed along with about 25ft of NFT pipe.

have you filled up your tank to check for leaks?  the hardest part of setting up my system was rebuilding the 55 gallon aquarium i got for free!  often times there's a very good reason the tank is free.  ;)

[Chi Ma]

Here is a tutorial.

[Averan]

yes.  yes.  1 inch.

[wes]

Justin, Wes here I just ordered myself this 1 inch drill bit and bulkhead for drilling my tank from BulkReefSupply, I get nothing from them for this just wanted to help you out as far as price goes for the bits and bulkheads. This drill bit was the most cost effective one I could find anywhere. If you need another size just call them, thats what I did and the tech on the phone told me what size bit would work for there one inch bulkhead fittings. The drill bits on the site are listed in MM so I needed some help in picking the correct size fittings and bit.

 

Product Name	SKU	Price	Qty Ordered	Qty Shipped	Qty Canceled	Subtotal
1” ABS Bulkhead Slip X Slip	202948	$5.99	2	2	0	$11.98
45 mm Diamond Coated Glass Drill Bit	203001	$14.99	1	1	0	$14.99
Order Subtotal						$26.97
Shipping & Handling						$4.07
Grand Total						$31.04

 
Justin said:

Did you use a pvc bulkhead fitting on the aquarium? Did you pipe it from the hole at the top to the FT bottom for solids pick up? What diameter would you recomend? I was thinking 3/4" or 1". Looks like I will be running to the hardware store today!

 Averan said:

in order to achieve a constant height in the fish tank, overflowing into the sump, you MUST cut a hole in it.  either that or let the water fill up and spill out everywhere....not exactly desirable in any situation.  order yourself a cheap glass hole saw and drill baby drill!  it takes a while, but is well worth the effort.

i've got a 55 gallon tank with 8 koi overflowing to a 30 gallon sump powering a 50 gallon grow bed along with about 25ft of NFT pipe.

have you filled up your tank to check for leaks?  the hardest part of setting up my system was rebuilding the 55 gallon aquarium i got for free!  often times there's a very good reason the tank is free.  ;)

[TCLynx]

For a 50 gallon tank, a 1" pipe drain is the smallest I would dare go.  I"m usually telling people to go bigger (you can always use a bushing to reduce it down but if you drill too small a hole there is little you can do to fix it other than putting yet another hole in the tank.

[wes]

I agree with TC a one inch is the way to go at the least, the tech I chatted with said the same thing about what is the best pipe size for the tank, but we were talking about a 55 gal tank in my case.

TCLynx said:

For a 50 gallon tank, a 1" pipe drain is the smallest I would dare go.  I"m usually telling people to go bigger (you can always use a bushing to reduce it down but if you drill too small a hole there is little you can do to fix it other than putting yet another hole in the tank.

[TCLynx]

I Had a 1" drain plus an extra 1/2" overflow on my 40 gallon aquarium and I had to be careful not to overflow it Make sure you hook up a bypass off the pump with a valve to allow you to let some flow back into the sump tank in case you have too much flow for your drain on the aquarium.