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?

 

 

[wes]

TC your wisdom amazes me you are so right thanks for the super insightful tip, Your just the best :)

[TCLynx]

Thank you, but I'm just repeating what those before me have taught.  A bypass is a great way to regulate flow without choking your poor pump.

[Averan]

good point.  my 1" is not quite enough and forces me to modulate water flows to keep from overflowing.  go with a 2"!

[Justin]

Thank you everyone for all the great advice. I am eager to get this project going. The pump I ordered came in the mail today but unfortunately was cracked and broken in shipping. I will hopefully get a chance to cut and plumb the tank this weekend. I have been starting plants in a home built aeroponic fogger, so I should have plants ready to transplant when everything is put together.

[Justin]

I looked at plastic bins from home depot and was surprised at how many didnt have a recycling number or symbol. I know PP, LDPE and HDPE are food safe but what about the unmarked ones? I have seen pictures of people using some of the unmarked bins that I saw. How much risk is there of leaching from these plastics? I was particularly interested in the 25 gallon tough box that is black with a yellow lid to use as a sump tank.