Bottom drain drilled tanks

[Argentum]

I am planing on building a 75 Gal grow out aquarium with auto/semi-auto water changing system. I want to make it as least labour intensive as possible.

I thought of drilling the aquarium from the bottom making 2 or 3 holes distributed along the length of the aquarium and covered with a mesh with big holes. (But not too big to drain the fish obviously). Somthing like what you have in a kitchen sink. The idea is to drain the solid waste along with the old water, therefore combining water changes with waste siphoning

I just wanted to see if anyone here has done it before or saw it anywhere?
How effective was... etc?

[Skip]

make sure you before you even DRILL the bottom glass first.. look at the labels at bottom edge of tank..

[Argentum]

make sure you even DRILL the bottom glass first.. look at the labels at bottom edge of tank..

I am going to build the aquarium using regular glass. Which can be drilled.

[Skip]

I am going to build the aquarium using regular glass. Which can be drilled.

ok.. so you know the difference between tempered and un-tempered glass..

good

[Argentum]

ok.. so you know the difference between tempered and un-tempered glass..

good

Sure. It is going to be un tempered glass. Or I might even go with acrylic

[MendoMan]

They make strainers that you can screw into the bulkhead if you get the proper size. I have that setup on mine but i'm only using one of the bulkheads for the drain the others are capped off. There are many types of bulkheads. To do what you want get the ones that are threaded on both ends. Use both non-toxic pipe dope and teflon tape on the threads for your valve and hose bib.

[nc0gnet0]

Are you going to install a flush valve/float and a rear tank as well?

[Argentum]

They make strainers that you can screw into the bulkhead if you get the proper size. I have that setup on mine but i'm only using one of the bulkheads for the drain the others are capped off. There are many types of bulkheads. To do what you want get the ones that are threaded on both ends. Use both non-toxic pipe dope and teflon tape on the threads for your valve and hose bib.

Thx for the tip. Do you have any pictures of your setup


Are you going to install a flush valve/float and a rear tank as well?

What I have in mind at the moment is similar to what you said.

1- Manually open the valves to drain the water
2- When the water reaches 20% open the water valves connected to the Flush float, while maintaining draining
3- Close the drain valve and once the water reaches the float valve set height it automatically shuts off.

Regarding the water source I will most probably use direct tap. In the building I am living in municipal water is stored in an underground holding tank, and temperatures tend to get very high at noon so I don't think there will be any chlorine/chloramine in my water I am using prime till the moment, however will order a kit and test my water to confirm.

I will also check if splashing the water against the tank wall will remove any chlorine that has not evaporated yet.


So is this system effective in removing solid wastes?

[SMB2]

Would not put drain holes in the tank bottom. If one leaks then you loose all the water and the fish die.
Would drill in the back about 3/4 the way down and add an elbow with down pipe when doing %100 WC.

[Argentum]

Would not put drain holes in the tank bottom. If one leaks then you loose all the water and the fish die.
Would drill in the back about 3/4 the way down and add an elbow with down pipe when doing %100 WC.

I understand that this is a risk. But if I do it this way it will defy the original purpose.

I will just have to take extra safety measures in order to prevent leaks.

And if it happens and leaks the float valves will start adding water as the level drops

[MendoMan]

Holes in the bottom are not much of a risk. Nearly all reef tanks are set up that way ( 2 holes for water to sump and 2 holes for return) properly installed bulkheads are fine.

[Second Hand Pat]

I am presuming you are adding the drain holes to be flush with the bottom of the tank since the goal is to remove the solid waste and the force of the water leaving via the drain hole will be pretty strong to accomplish that goal. My concern is having the fish get caught by the suction of the water leaving the tank and getting a pretty serious hickey and/or getting injured. Honestly I prefer to monitor my WCs plus the growout tank still needs to be wiped down.

[Argentum]

This is one of my concerns but I have thought of two ways to prevent a fish bring sucked by the drain.

1- Making multiple drains, maybe 3 one in the middle and two at the edges. This will reduce the amount of suction required by each drain because it will be covering a smaller area.

2- Installing protective covers over each drain hole - I don't know what to call them- to prevent the fish from covering the drain hole. something like this:

http://i1159.photobucket.com/albums/p634/argentumblade/vent-pipe-screen-4-inch_zpsb626b661.jpg (http://s1159.photobucket.com/user/argentumblade/media/vent-pipe-screen-4-inch_zpsb626b661.jpg.html)


I am presuming you are adding the drain holes to be flush with the bottom of the tank since the goal is to remove the solid waste and the force of the water leaving via the drain hole will be pretty strong to accomplish that goal. My concern is having the fish get caught by the suction of the water leaving the tank and getting a pretty serious hickey and/or getting injured. Honestly I prefer to monitor my WCs plus the growout tank still needs to be wiped down.

[nc0gnet0]

Thx for the tip. Do you have any pictures of your setup



What I have in mind at the moment is similar to what you said.

1- Manually open the valves to drain the water
2- When the water reaches 20% open the water valves connected to the Flush float, while maintaining draining
3- Close the drain valve and once the water reaches the float valve set height it automatically shuts off.

Regarding the water source I will most probably use direct tap. In the building I am living in municipal water is stored in an underground holding tank, and temperatures tend to get very high at noon so I don't think there will be any chlorine/chloramine in my water I am using prime till the moment, however will order a kit and test my water to confirm.

I will also check if splashing the water against the tank wall will remove any chlorine that has not evaporated yet.


So is this system effective in removing solid wastes?

So, a tank design that acts as a big toilet.....lol.

[Larry Bugg]

A little over halfway down the page you will see the intake screens.

http://www.jehmco.com/html/bulkhead_fittings.html

I believe you will find that what you are trying to do will not eliminate cleaning the bottom of the tank with a siphon tube. There will not be enough suction generated to lift everything off the bottom. It won't be nearly as much suction as you think it will be. My drains are not drilled in the bottom but are within 1" up the backs. I still have to siphon with each cleaning. Every once in a while I will forgo the siphon and try to flush out the bottom with the force of the refill water but I am never happy with the result. Keep in mind that you are not reducing the flow rate of each bulkhead by adding multiple bulkheads, or not by much, you will just reduce the amount of time it takes to drain. A 1" bulkhead has an amount it will drain based on volume of water and the pressure created by the height of the water. Also, keep in mind that multiple bulkheads draining at the same time will require a larger drain to go into. I have 1" bulkheads on my tanks and they drain into a 1 1/2" drain pipe. The drain pipe cannot handle the flow from two 1" drains at one time or it will back up. If you have 3 1" bulkheads in a tank you will need a very large drain pipe to handle the flow.

[Argentum]

So, a tank design that acts as a big toilet.....lol.

HAHA well .... basically yes LOL. It will operate as a 70+ gallon flush

[Skip]

HAHA well .... basically yes LOL. It will operate as a 70+ gallon flush


https://www.youtube.com/watch?v=UFq-d8u5Px8

like this..

[Argentum]

A little over halfway down the page you will see the intake screens.

http://www.jehmco.com/html/bulkhead_fittings.html

I believe you will find that what you are trying to do will not eliminate cleaning the bottom of the tank with a siphon tube. There will not be enough suction generated to lift everything off the bottom. It won't be nearly as much suction as you think it will be. My drains are not drilled in the bottom but are within 1" up the backs. I still have to siphon with each cleaning. Every once in a while I will forgo the siphon and try to flush out the bottom with the force of the refill water but I am never happy with the result. Keep in mind that you are not reducing the flow rate of each bulkhead by adding multiple bulkheads, or not by much, you will just reduce the amount of time it takes to drain. A 1" bulkhead has an amount it will drain based on volume of water and the pressure created by the height of the water. Also, keep in mind that multiple bulkheads draining at the same time will require a larger drain to go into. I have 1" bulkheads on my tanks and they drain into a 1 1/2" drain pipe. The drain pipe cannot handle the flow from two 1" drains at one time or it will back up. If you have 3 1" bulkheads in a tank you will need a very large drain pipe to handle the flow.

Thank you for the tips, such info will help me with the design

[Argentum]

Okay fond something, I think in the end it will look like this:

https://www.youtube.com/watch?v=YWMnPZKJWaE&feature=youtube_gdata_player

The video is from Lawrence's farm

[Second Hand Pat]

Note that as the water is nearly drained from the tank water is added to the tank to help flush the soiled water/waste from the tank prior to the drain valve being closed.

[SMB2]

[QUOTE]Making multiple drains, maybe 3 one in the middle and two at the edges. This will reduce the amount of suction required by each drain because it will be covering a smaller area./QUOTE]


Not sure this is "hydro-dynamically" correct. The flow out the drain is related to the size of the hole and the hight of the water column. Not the number of holes. The rate of flow will reduce as the water level drops.

Somebody correct me if that is wrong.

[nc0gnet0]

Not sure this is "hydro-dynamically" correct. The flow out the drain is related to the size of the hole and the hight of the water column. Not the number of holes. The rate of flow will reduce as the water level drops.

Somebody correct me if that is wrong.

It will be limited to the point of most restriction. 3 holes would drain faster*, but alot will depend on what the three drains ultimately dump into. As Larry pointed out, if three one inch lines dump into a single 1 1/2" line, there will be your point of most restriction. However, if they dump into a 4" drain pipe, then they would effectively be 3 x as fast.

* now for the hitch, while they may indeed be three times as fast, they could counter act each other and reduce the effectiveness of pulling waste/debris from the tank bottom. You would be better served by one larger hole, and the design would be much more effective if the tank was cylindrical. If you want this to work reasonably well, you would want a tank like this:

http://www.tropicalfishstore.com/images/cylinder80dark.jpg

(image taken from http://www.tropicalfishstore.com/Aquarium-cylinder.htm)

I really wasn't kidding when I said to think about how a toilet works.

[Argentum]

* now for the hitch, while they may indeed be three times as fast, they could counter act each other and reduce the effectiveness of pulling waste/debris from the tank bottom. You would be better served by one larger hole, and the design would be much more effective if the tank was cylindrical. If you want this to work reasonably well, you would want a tank like this:

I really wasn't kidding when I said to think about how a toilet works.

When a cylindrical tank is not possible I will still have to go with our rectangular tank.

How will they counter each other? are you speculating? or you know it?

It can be reduced to 2 on at each third of the tank, but I cant imagine that it wil pull waste away with 60 cm . although the water splashing from the float valve will move things around.

[SMB2]

I guess what I was trying to say was that if all the holes are the same diameter, the flow through any one hole will be the same, whether there are three or twenty holes and the rate will be determined by the hight of water in the tank (and as you point out any other restrictors down stream).

If the detritus is in suspension, some will always be left behind during the WC. If you are hoping that the current to the drain will pull the detritus into it thus avoiding vacuuming, not sure that would be all that effective. And while all this flushing is going on, what are the fish doing?
Let us know if it works. Time to invent a small automatic pool vacuum for bare bottom tanks that gently keeps the bottom of the tank swept 24/7.

[kwan8911]

You might consider adding 2 or more power head, 1000gph or more. When you are draining the water, turn on the power head. The poop and debris will be flying all over the tank and eventually get suck away by the drain hole.


Sent from my iPhone using Tapatalk

[Argentum]

Most of the waste will be on the bottom rather than suspended. So I want the sink holes to drag them out and when the water level falls, the splashing from the filling water (float valve) will disturb some of the heavier wastes. Off coarse I will still have to wipe down the glass once in a while to remove slime but overall this method shall reduce the maint. time

I will see how it goes and update here. I am open for suggestions until I start with the build.

Thx to everyone for your valuable input

[nc0gnet0]

Your much better off with one larger hole as opposed to three smaller holes working simultaneously together. Each hole will create it's own vortex with water circulating around the hole. If you get three working at the same time, the vortex of one hole will interfere with the vortex of the other hole, thus decreasing it's effectiveness to suck debris out of the tank. It might be effective if you were to have three holes to drain a portion of the tank at one location, then close that drain up and begin draining at another location, and so on with the third drain hole. This however seems like a lot of additional hassle to deal with, so you will find it far more effective to have a centrally located 2-2 1/2" hole instead of three. All modern plumbing that relies on drainage utilizes this concept, sinks, toilets, etc.

[paulW]

I am planing on building a 75 Gal grow out aquarium with auto/semi-auto water changing system. I want to make it as least labour intensive as possible.

I thought of drilling the aquarium from the bottom making 2 or 3 holes distributed along the length of the aquarium and covered with a mesh with big holes. (But not too big to drain the fish obviously). Somthing like what you have in a kitchen sink. The idea is to drain the solid waste along with the old water, therefore combining water changes with waste siphoning

I just wanted to see if anyone here has done it before or saw it anywhere?
How effective was... etc?

In any automatic water changing system, you should put a bulkhead near the top of the tank which is piped to a drain and always "open"
That way when something goes wrong with your automatic topoff system, the extra water is drained instead of flooding your house.
Just remember, everything fails eventually. It took me about 8 floods to realize that lol.

Drilling a hole at the bottom of the tank is fine. However, I recommend spending a little extra for a schedule 80 bulkhead if you drill in the bottom of a full tank. The cheaper schedule 40 ones are more prone to leak in larger tanks, at least I had two that leaked on me when the water column was 30" high. Maybe in a 75 gallon (which is only 18" high, I think?), a schedule 40 is good enough, but it really doesn't cost that much more to upgrade your bulkheads , especially if it is just one.
So far, I haven't had trouble with schedule 40 drilled near the top (like for an overflow).. Much less pressure there though.

[nc0gnet0]

In any automatic water changing system, you should put a bulkhead near the top of the tank which is piped to a drain and always "open"
That way when something goes wrong with your automatic topoff system, the extra water is drained instead of flooding your house.
Just remember, everything fails eventually. It took me about 8 floods to realize that lol.

Drilling a hole at the bottom of the tank is fine. However, I recommend spending a little extra for a schedule 80 bulkhead if you drill in the bottom of a full tank. The cheaper schedule 40 ones are more prone to leak in larger tanks, at least I had two that leaked on me when the water column was 30" high. Maybe in a 75 gallon (which is only 18" high, I think?), a schedule 40 is good enough, but it really doesn't cost that much more to upgrade your bulkheads , especially if it is just one.
So far, I haven't had trouble with schedule 40 drilled near the top (like for an overflow).. Much less pressure there though.

You can accomplish the same thing with a bottom drilled tank and some extra plumbing. need to run the drain pipe horizontally across the bottom of the tank to the backside, install a elbow and bring the pipe straight up the backside then do a 180 and back down. How high up you put the loop will decide the maximum drain point of the tank. This would prevent the dreaded, completely empty if something go's wrong scenario.

[paulW]

You can accomplish the same thing with a bottom drilled tank and some extra plumbing. need to run the drain pipe horizontally across the bottom of the tank to the backside, install a elbow and bring the pipe straight up the backside then do a 180 and back down. How high up you put the loop will decide the maximum drain point of the tank. This would prevent the dreaded, completely empty if something go's wrong scenario.

Good idea. I've seen someone else do this loop plumbing and it seems to work well.