Pumps

[Caesars]

Ok, down to the pumps now I and I will stop pestering you. The new zebbie tank will be 700 litres. I therefore reckon I need a couple of pumps with an output of 4500 an hour - or thereabouts.
At the moment in my big tank I got Eheims but I am not 100% pleased with them as the impeller keeps dislocating and I am having occasional problems with back-syphoning. Can anybody suggest any reliable and QUIET pumps with this output? Or, any other pumps you are using provided they are sump-based. Thanks!

[LyreTail]

wow - that is huge for Zebras?. I thought I was running a large tank for them at less than 1/4 that amount. I am using a 150 liter 4 foot long tank

I think for a 700 liter tank you may have to use multiple pumps or a large pump like an AquaClear 901. The pumps underwater do not make that much noise, but adding the venturi aeration and all the bubbles tend to make some noise. I think the extra aeration is helpful though. Replicates a fast moving stream with maximum oxygen content.

Maxijet is another brand that seems to be trustworthy

[Caesars]

Thanks Lyretail After serious consideration I decided to go for the Tunze, 9000 lit per hour. That should be ok for them! Fingers crossed tank should be here in two weeks - can't wait! I was quite particular in getting something as noiseless as possible as I noticed in the past they hate noise. On one occasion I put the Aero in and they all moved to the other side of the tank. As for the capacity, it won't be all tank, some of it will be sump too! I thought I would go for that size as I plan to leave the babies (when my dears oblige) in the tank to grow with dad. So I am planning two colonies - one with Caesar and one with Fiesty. Lets see ...
The tank will have two pumps - Tunze will be the main one then there will be another one just for circulation - going through a UV steriliser. Have you used the ones you mentioned? How quiet are they?

[LyreTail]

you are going to run about 2 x the circulation rate that I am running. That is a huge pump. Might be necessary if the tank you are getting is extra tall. My river tank is only about 40 cm tall 30 cm wide and 122 cm long so 6 times turnover provides so much circulation that the Plecos actually look uncomfortable

I have used both brands of pumps I mentioned, the noise is associated with the aeration device ( venturi) and that can be pulled off or adjusted down to small levels. I tried to choose pumps that I saw on UK web sites. The other two pump brands that I have used are Penguins and Rios

[NetsuaiAngel]

*flying zebra*

[Caesars]

you are going to run about 2 x the circulation rate that I am running. That is a huge pump. Might be necessary if the tank you are getting is extra tall.

The tank will be 60 cm tall, 60 cm wide and 150 cm long. There will be a full lenght sump with it. What do you think? There will only be zebbies in there - except if I temporarily house the Queen Abbies there too. The reason I went for this size (though I would personally prefer smaller as they are easier to maintain and should there be an accident it doesnt affect all the fish) is that I have to remover furniture to have more tanks for the time being. I am planning an extention in future .. but I need space now! (tank space I mean). I am putting the exit of the water across the bottom so that the water flow spreads and hits about the middle of the entrance of the caves (1 1/2 inch from the bottom). I have read that zebbies are fine with any flow between 6 - 30 times an hour, so I thought the 12 times an hour this will give them should be fine. But I have 2-3 days to change the order if need be. What do you think?

My river tank is only about 40 cm tall 30 cm wide and 122 cm long so 6 times turnover provides so much circulation that the Plecos actually look uncomfortable

Are these zebs? How many have you got there? I am housing some smaller zebs (the ones I got from Imer) temporarily at present in a 100 lt tank with a 10 times per hour turn over and they look fine!

[LyreTail]

I just have 5 zebra Plecos and nothing else in the 40 US gal tank. They tend to reside down in the final 1 foot of tank length farthest from the pump where I placed all the caves per other peoples thoughts on this site.

As far as flow rates are concerned, I have heard several people say very high flow rate and others say that it is not as important ( such as McEve told me) My Plecos seem to be more active in a tank with a lower flow rate, but that may be a function of the height and width of my tank giving the Plecos a more intense flow rate. I choose this long and low style of tank on purpose in order to simulate the river flow more accurately

I tried putting Java ferns in the tank, but they burned up just like Barbie said they would when I raised the temp to try to trigger spawning

When you say "full length sump" I assume you are speaking of a wet dry filter that is built in along the back wall of the tank. These are great built in filters that normally use bio balls or some other such bio media, but you should check with the tank's manufacturer to make sure the sump will handle such a high flow rate. Sometimes if you place too powerful a pump in these pre installed systems they can drain one side or overfill the other side of the sump.

[Caesars]

Wow LyreTail, your guys have enough space to play football in there! By sump I am referring to a water container under the tank. One part of it houses the biorings, then there is a compartment for heaters etc, and then a clear water compartment which also houses the pumps. I have a sump currently in my tank and it has 200 lit capacity. The tank is ordered with the specs of the pumps (as they need to drill appropriate holes etc) and it will have two water exit points to ensure that the intake and exit are evened out and what you mention doesnt happen.

Interesting to hear your comments about the flow rate!!! I shall have to monitor that, but now you have put me in deep thought ... I thought I had it cracked with the Tunze I think I will make some enquiries about high turnover pumps with adjustable flow rate! Do you know of any?

[LyreTail]

Oh you do mean a real sump I was thinking a built in system along the length of the back wall which are real neat setups but expensive.

If your sump has trouble with the flow rate you can increase the diameter of the intake pipe and increase the overflow ability.

The higher you pump water from under the tank to the top of the tank, the more power you need in your pump. You will have a 6 decimeter tall tank ( 60 cm) , and the stand may be as much as 9 decimeter tall. This is a significant distance to push water up, so you may need the power of the Tunze

A smaller return pipe creates more water pressure, but will restrict volume of water flow

[Caesars]

Ok so here are the measurements, tell me your view: The tank stand, in which the sump is located, will be 30 inches. The tank will be two foot tall (60 cm). Therefore the water will go all this way up then down again inside the tank and will exit from a long pipe with little holes alongside the lenght of the tank. I have asked for the pipe to be 1 to 1 1/2 inch off the bottom, so that it actually gives the current round about the middle of the entrance of the caves you sent me. I haven't yet specified the diameter of the pipes but any ideas are welcomed. To allow for the faster flow rate there will be two exit points (in the tank) for the water, equidistantly placed from the ends of the tank. What do you think?

[LyreTail]

I am unsure of the exact diameters of pipes needed. Many times where the flow restrictions are, are in bends, elbows, spray bars or valves.

If I calculate 9,000 liters per hour and calculate water velocity through a 1.25 inch internal diameter pipe, I get about 625 foot per second of water flow. If I go up to a 2 inch diameter pipe then I get about half the velocity

How are you going to handle the overflow?
1. Built in corner over flow
2. Hang on back overflow siphon box
3. Exit holes drilled from the bottom or back of the tank and pipes stick up like a stack using bulkhead fittings
Any over flow should have a prefilter sponge to stop fish fry from entering. The over flow side should be able to take slightly more volume than the pump return side just to avoid problems with sump trying to empty itself into the tank - Another concern on this line of thought, is tank overflowing from the sump volume. This happens when the overflow side of the system gets clogged and the pump tries to push all the sump volume into the tank. I am not quite sure how to handle this unless there is some sort of automatic pump shut off you can install for when the sump drains to a certain critical level
http://reefcentral.com/calc/drain.php
http://www.reefkeeping.com/issues/2003-07/gt/index.php

Pump return pipes
There are several ways to handle this. This setup would have a uni directional check valve in-line to stop the water from draining back into the sump if the spray bars are going to be low down inside the tank. Normally a spray bar exits at the top of the tank so this is not a concern. It would not hurt to have redundancy's in the check valves. I think the return pipes / spray bar should be about 1/2 the diameter / volume of the exit pipes.
http://www.reefkeeping.com/issues/2002- ... /index.php

I would also include manual ball valves on both sides so you could shut them down for some reason. They may come in handy when testing the first run. Either way you decide to design such a system, you must account for power outage or turning the pumps off for maintenance. Sump must have enough dry room to accept the additional drainage from the top of the overflow when the power goes off .
http://reefcentral.com/calc/sump.php
This is the main reason sumps are so big compared to other types of filtration methods.

[Caesars]

Thanks LyreTail, that was very useful.

I am unsure of the exact diameters of pipes needed. Many times where the flow restrictions are, are in bends, elbows, spray bars or valves.

So what we are saying is that the capacity of the pump is "under factory test ideal conditions" (whatever these may be) but the flow in the tank will always be less than the factory specs of the pump.

If I calculate 9,000 liters per hour and calculate water velocity through a 1.25 inch internal diameter pipe, I get about 625 foot per second of water flow. If I go up to a 2 inch diameter pipe then I get about half the velocity.

How do you calculate velocity?

How are you going to handle the overflow?
1. Built in corner over flow
2. Hang on back overflow siphon box
3. Exit holes drilled from the bottom or back of the tank and pipes stick up like a stack using bulkhead fittings.
Any over flow should have a prefilter sponge to stop fish fry from entering.

I was thinking built in corner overflow. I have that in my current tank and to-date I have not had any problems - other than fry getting through and ending up in the sump. I will have to try pre-filter this time I thought the plants that I had round it and the biorings (its filled to the brim with them) would prevent the fry going down. Wrong! Btw, the third solution you cite - it sounds a bulky construction and one would have to find ways to "cover" the pipework from showing inside the tank - does it have any particular benefits over number 1?
Manual turn offs sound like a good idea - consider it done

[LyreTail]

Yes to the fact that pumps never actually pump what they say they pump unless you are using an internal pump that does not have any friction or head loss. It is actually quite a complex equation to predict actual flow rate and most efficient pipe sizes. If you go too small on pipes then you increase velocity and slow volume flow. If you go to too large diameter of a pipe then you will loose velocity and increase the weight of the water you are trying to push up wards, which will also slow rate and possibly burn up a pump - remember about twice diameter on overflow side than the return side to insure less clogging on the overflow side. If the overflow side clogs this can result in the sump emptying into the tank causing a flood..

Here is a simple little velocity calculator
http://www.tasonline.co.za/toolbox/pipe/velocity.htm
Even with a 2 inch dia pipe using your Tunze flow rate number, I get a velocity of 4 feet per second, not taking into account any " dynamic head loss" which or course there will be. So say you go to the 2 inch pipe then you might expect at least 3 foot flow rate per second. If you have a 6 foot tank then new water rushes from one end of the tank to the other end in about 2 seconds. One way to resolve the intense flow rate besides increasing pipe diameter is to raise the spray bar higher in the tank so the Plecos do not get the full brunt of this very quick flow. Raise the spray bar up 1.5 foot off the floor and the direct flow at the bottom of the tank lowers a lot. This is probably one of the easier adjustments you can make.

As far as the overflow designs - the pipe stacks work just like the corner overflow and would be a little smaller. I agree a built in corner overflow is a more attractive and stronger design. Get a lip built into the top of the corner over flow to receive a tray with holes drilled into it. The tray will hold some open celled foam or some of the poly fiber material sold for filters in bulk sizes that can be cut to fit. A course poly filter mat or foam is better than fine , so that cleaning is less intensive. You can put the more fine mechanical media down in the sump itself for easy access. For easy access you can also have a removable window in the tank lid right above the overflow area so you can clean this pre filter on top of the overflow when ever you need to. This is a very practical and easy to maintain design that many acrylic aquarium makers have adopted

http://www.reefkeeping.com/issues/2003-01/gt/index.php

[Caesars]

Lyretail, thank you very much for all the info and the help, you are a real technical gem!! I have finalised the order today taking into account your comments. I will have manual stops on the intake pipe and on the sparybar. To get round the issue of velocity I am having the spraybar pushfit or screwon - which will allow for re-orientation if necessary. The size of the wholes will be variable to allow for softer current hitting the fish. I think I need to monitor the strenght of the current in practice and adjust it from there - I may need to pick your brains again on this one

Once again, thank you for all the help and ideas !

[LyreTail]

No problem. I spend most of my hobby building stuff and inventing new filters and tank designs. My CO2 reactors and automatic live bearing fish fry trap are my best designs I have come up with so far. I have a new river tank Idea that I think will be very nice looking, but I will probably wait until next summer for that project. The cave making has sort of taken over my project time in the past several months, but I am taking some time out right now to complete a media cabinent that I am making for my sister as a Christmas present.

If you have trouble with the pump you can always get a slightly less powerful pump. Sometimes putting together these systems is a little bit "trial and error" but many times I have found that these designs can also be forgiving to a certain extent.

Once you get your tank and assemble it. You should run a pump shut off test and watch what happens. The reason is that you never know when the power or the pump may fail and you want to know what will happen if this happens. The last thing you want is to not have enough extra room in your sump to handle the overflow drain volume. This can also be easily calculated by figuring for drain level to top of overflow and adding that to the volume of the overflow chamber. This total volume needs to be able to be handled easily by the extra sump volume. Nothing beats an actual physical test though