Terrarium questions
 

:helloagain.

I've been looking around for external water pumps and filters for my aquarium but all I've found so far are submersibles, it seems they no longer make the external types. Does anyone know where to find the externals? I want the pump and filter on the outside of the tank. It's necessary since the tank is only 12 inches deep i.e. front to back.

Five "Mini"-Phals and one Bromeliad presently inhabiting the tank.

There are two tops with florescence lights with T8 (full spectrum) bulbs. They are on during the day and off at night. So far there are no apparent sunburns.

As it stands now there will be between one and two inches of water in a "pond", a waterfall in one corner and a couple of "springs" somewhere in the land-form.

Are Phals able to be mounted horizontally and vertically?

Haven't decided on branches/limbs yet as I understand any mounting medium needs to be sterilized.

Haven't decided what other plants to include, that will come later.

Well more later.

Robert

Do you have any pictures of your setup? It would help give an idea of what you are trying to do. I'm having a hard time picturing how a pump or filter will work with 1-2 inches of water.

You seem to be looking for an external canister filter. There are many different brands and sizes readily available. The typical "hang on back" filter won't work with low water levels. As long as you can keep both the intake and outlet fully submerged any canister will work. They're not designed to pump water up, but rather to circulate it. Once all the air is purged from the system, that's what they're doing. If you plumb it so the outlet is above the water line, say to create a waterfall effect, you introduce what is known as "head pressure" into the equation and will need a much larger unit than you would normally use for your size of tank.

So far there is only the bare 55G tank. I'm still at the designing stage of the background, haven't even committed it to the drawing stage.

Since the tank is only 12in deep (front to back) it is necessary to maximize the growing space.

The water level may have to go to 3in but I hope not, the height of the tank is only 19in.

I do have an unused pond pump but it to is submersible so I'd have to pump water out, design some sort of bypass to reduce the flow rate then send it back into the tank. Might be a big problem.

Robert

---------- Post added at 07:49 AM ---------- Previous post was at 07:44 AM ----------

Subrosa

The waterfall feature along with a couple of springs is what I intend so much planning and investigating is still ahead. (Also see #4 above).

Robert

Why would you want an external pump for a water feature? External pumps do exist, but they are expensive, generally in the hundreds of dollars and they move way, way more water than you need for water features in terrariums. We're talking hundreds of gallons per hour. That's reef aquarium flow. You don't need that kind of power in a terrarium.

Given your desired outcome, you should look at using MaxiJet 1200 powerheads. They'll pump water high enough to run a waterfall in a 55, and are very inexpensive. One important caveat! There are currently two different manufacturers making them, Marineland and Cobalt. Marineland's are about 1/2 the price of a Cobalt ($20 vs $40) and are what is known as a "new style" Maxijet. They're junk! I got failure rates approaching 20% in the first year using them to run auto top offs for my customer's reef tanks. I use only Cobalts for my customers now and have no issues at all with them. I believe it's something in the design, because I have a couple of "old style" MJs made by Marineland that are at least 20 years old and run like new.

They replaced the ceramic impeller housing with plastic, that's why the marine land MJ's break.

MJ's are submersible the impeller will shred if they are ever run dry and they are noisy, but they would work.

Years ago I bought a Beckett G535 submersible pump for a pond I planned on but never got around to making. At about a 5ft head of it is supposed to deliver approx 300+GPH which is probably more than I need but I can, and will if necessary, divert some of the output back into the tank it will be living in. Too, the instructions state a restriction can be placed in the feed side of the pump. I suspect I will have to adr a ball valve somewhere in the feed pipe to to adjust the flow back into the tank. (The tank the pump will be in will be on the floor rather than in the terrarium).

Robert

"external water pumps"

https://www.google.ca/#q=windshield+washer+pump

You sound like you're describing a system with a sump. Is this correct?

Yes, the sump will sit on the floor next to the cabinet it is sitting on.

Robert

Is the 55 drilled on the bottom?

No way! :) The terrarium is made of tempered glass. Can't drill tempered glass! At least I can't.

The feed and returns will be over the top at one corner of the tank where the waterfall will be.

Shortly I plan to start a new thread in the Terrarium Gardening forum tracking the progress of creating it ("it"=for orchids (of course:blushing:)).

Robert

How do you plan on getting water to return from the tank to the sump? If you're thinking you'll pump it back down, start thinking differently!

Terrarium questions
 

Oh good question! I'm loving this thread. I want to build a natural looking waterfall in my terrarium too, but have no idea where to get started so I'm learning a lot!

I understand where you're coming from and, indeed, it may be a tricky situation but hopefully I've got that covered. The main problem will be to fill the return tubing before starting the pump the first time. Once it is running it will be a closed system and the only reason for the "sump" will be cooling the pump. Granted this is all theoretical: the weight of the water returning down the return tube should balance the weight of the water being pumped up the feed tube. If that is, indeed, the case there won't be much load on the pump.

Whether or not this will work in reality depends on how hot the body of the pump gets (bearings mostly). I'm expecting the amount of water in the "sump" will keep the pump cool enough. There are two reasons I expect this system to work: 1) the motor is thermally protected and 2) the water moving thru the pump provides the cooling for the shaft seal. Also the "sump" is a plastic container

There are only two caveats I can see here: 1) filling the return tube (not quite sure how to accomplish that yet) and 2) how warm the water in the tank becomes, can't have it get too hot for the orchids. I don't anticipate the sump water getting too hot as the sump will be on the floor which stays relatively cool even in the summer.

So to this extent this is an experiment. Guess I'll have to run the system before the orchids are introduced.

If worst comes to worst the pump will have to be in the tank. I don't want this as I want to have as much growing space in the tank as possible. Too, to have the pump in the tank would mean three inches of water.

Robert

---------- Post added at 12:02 PM ---------- Previous post was at 11:49 AM ----------

Actually I've been going over stuff here that properly belongs in the Terrarium Gardening section which I suppose I should get started on it. The plan now is to record the process step by step with pictures. So wander over there in a couple of days. It will be a learning experience for both of us (and others).

Robert

So there will be a sump. How much water in the sump? What happens when the siphon breaks? It will pump all the water from your sump into the terrarium and flood it. Its sounding more and more like your best bet is to increase the depth of the water and use a submersible pump in the tank.

Not going to work Robert. Your design requires you to, from a physics standpoint, have your cake and eat it too, in that you are trying to combine an open system with a closed system. In a closed system you could indeed get all the air out of your return tube and have water return nicely to the sump. But a waterfall is by definition an open system, which will allow air in which will stop your siphon. I've been installing and maintaining aquaria professionally since the early 90s, and if I had a nickel for every time I've heard someone want to try what you are planning I'd have a few bucks. If I had a nickel for every one I've actually seen, I'd have a nickel, and if I had a nickel for every one that worked long term I'd be broke! The only sensible way to get water from the main tank to the sump is gravity. The only non-sensible way that works is to use a second pump on a float switch, which will one day fail. In your case that would result in a burned out pump in your sump. In the one case I've seen of someone actually doing it, they ended up with about 20 gal of saltwater on their floor. You are correct in that tempered glass can't be drilled. If you want to run a waterfall in an undrilled tank, you will end up putting the pump in the main tank. Save yourself a lot of wasted time and design around it. This is not an opinion, it is physics.

:blushing:
You've made me think :hmm. The pump would only fail if the water level in the tank fell below the siphon inlet so it seems to me that if one continually checked the water level and added water as needed the system should continue to work.

In any case I'd planned to make a mockup of the system to check it before actually installing it so if it fails, well, at least I won't have installed it and find it went kaput. :_(

As for the waterfall introducing air into the system I can't see how that might happen since any air introduced thus wouldn't get into the return tube since it will be immersed in a pool of water.

***Thought experiment: Put two pipes into a large watering trough and the other two ends attached to a pump of some sort, start the pump or hand crank it. It should pump until the water level drops below the suction pipe. So would that be considered an open system or a closed system? Either way it will work indefinitely (or until the water level drops too far).

In any case I appreciate your input.

Robert

Water splashes. Splashes are air mixing with water. However since your system as laid out is an open one, a bit of air may not matter. But if enough gets in to break siphon, yyou'll burn out the pump. One way of addressing your concern about water depth with the pump in the main tank would be to install an elbow on the intake. This would allow the pump to function in much shallower water.

True, true if the waterfall and the siphon tube are in close proximity but in this case the water fall will go into a small pool then via a short creek to the main pool that will be under all the landforms and never near the incoming water.

Also with the pump in the tank if anything went wrong (and it will) I'd have to do a major demolition to get to it not to mention the extra space all the plumbing would take up. There's just too little space in a 12in wide tank.

In either case there is the need to constantly monitor the water level.

Robert

Never heard of an auto topoff unit, have you? It's a fairly simple way of maintaining a cconstant water level.

A great idea and yes I''ve thought of it but the terrarium is in the dining area no where near a water source so, unfortunately that possibility is out.

Robert

No room for a container under the tank?

Unfortunately no. The cabinet is the only flat spot in the house suitable for the tank and it is full of dishes and bowles.

Robert

Since your "sump" is really nothing more than a cooling bath for your pump, why not use it?

My friend, you can try an windshield pump under volted, let say 8V, if vork, works, if not is not too expensive and can be used for misting

I considered this but siphoning would mean sucking all the water from the tank thus emptying it and pumping all the water from the sump back into the tank, a truly open system and a sure method for burning out the pump.

Certainly something to consider since I will want a misting system.

It's much easier to maintain a steady water level in a larger container. If the level in your pool in the main tank drops too low it will burn the pump out just as surely.

Granted and that is why constantly monitoring the water level is necessary. The water level in my tank will, hopefully, be not more than 2 to 2-1/2 inches. We'll see how that works out.