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Brann
07/01/2009, 03:59 PM
As the topic says I have a Little Giant 3-MDQX-SC inline Pump and I am attempting to use to replace a failing main pump in my sump.

Specs:
# Flow rate: 1,100 gph
# Max head: 14 feet
# Connections: 1" FNPT in X 1" MNPT out

Now based on reading the manual I know that it is not build for the way my sump is setup... But, I was wonder if anyone has ran a pump the way I am thinking. If it is safe and if all I will do is lose out of some of the flow rate then I will be more than happy until I can get another pump that better fits my needs.


My setup at the moment breaks down like this:

I have a submersible pump in the last chamber of a 55gal tank I divided into sections for my return that goes to my UV sterilizer then to my display tank and out of spray bar in the back of my rock wall shooting up.

What I planned to try is to install the inline on the floor and then run a feed hose into the inlet of pump over the top of the tank into the chamber and start a siphon to feed the pump just like for a water change. While the pump is meant to be gravity fed from above or level with the output from a sump that has an output on the side I *assume* the flow of the water from my siphon would get the job done.

Assuming it works I figure these are the pros and cons....

Pros:
a. I can make use of this $160ish pump that has been collecting dust in my house.
b. I will not have to spend more money to increase the flow rate of my tank :)

Con:
a. The pump would need to be primed with the siphon each time kinda like my overflow box before use if turned off.
b. I would not have to have my sump drilled or replaced which would be more costly and more of a pain than just getting another submersible pump.
c. If the water level drops below my siphon feed line to the pump it would run dry.



Please let me know what your input is on this topic and/or if you have ever tried anything like this before. Keep in mind I am working on a shoe string budget and have more time than money to mess around with at the moment :)


Thanks in advance,
-Brann

Brann
07/03/2009, 02:26 PM
http://reefcentral.com/gallery/data/500/221904Dry-pump-diagram01WEB.jpg

Please excuse the diagram, but it was the first one ever with this new app :)


Here is the break down based on a test I did today:

I have replaced the wussy little giant pump with an IWAKI MD-55RLT. Earlier today I tested that pump with a 5 gal bucket, some 1 and 1/4 inch flex hose and a garden hose. I put the feed hose into the 5 gallon bucket and turn the pump on for a second. No flow as expected coming out of the pump as it is dry. I then stuck the garden hose inside the 1 and 1/4 inch feed line while it was inside the bucket to prime the pump and fill it full of water. Once I turned on the pump it started flowing instantly like a fountain. I removed the garden hose from the bucket and the pump drained that 5gal bucket in about 12 seconds :)

-----------

Based on this info I drew up these plans to attempt it full scale in my tank. As show in the picture my pump is in on the floor with the feed pipe ABOVE the inlet to keep the siphon going. I think this SHOULD work... but any input on my theory is more than welcome. The only issue I could see happening is me needing a smaller pump to prime the IWAKI if my water level drops low or I turn it off and the siphon breaks. Assuming this all works it will be returning to the sump via my ReefOctopus 1" pipe overflow box.

I have 90% of the parts already for this build and I figure the other stuff would only cost me about $20ish as hose that size is anything but cheap :(

Input please :)

-Brann

Gary Majchrzak
07/03/2009, 02:51 PM
I've seen what you describe here many times- it works. You'll just need to prime the plumbing in order to start up the pump. It looks like you already realize this.

There's a couple of things I don't like about your design here:

*back flow/check valves. They fail. It's just a matter of time until they fail IME.

*returns to spray bar on bottom. Without an anti siphon hole (or check valve) the whole aquarium could possibly back siphon to the sump. Aquarium design has improved since the early 90's when bottom spray bars were popular -make sure all returns discharge just under the water's surface and blow towards the overflow box.


there are threads archived on RC showing the external pump plumbed the way you describe here but I can't find any of them at the moment...

Brann
07/03/2009, 03:13 PM
Thank you for the speedy reply Gary!

See I am learning things already.... My magic spray bar is nothing more than a 1" PVC pipe T'ed and drilled with all kinds of holes pointing up to not hammer my sand with the return pressure of the water. I had a single pipe an inch below the surface when I first started and I did not like how it threw my sand out of place from the water flowing into the tank. Are there any major side effects to still using my spray bar? I would hate to have to remove it when more there a few critters call the area home....

Now this "anti siphon hole"....I was a little confused by your concern for the check valve on on return pipe, but then suggesting one on the spray bar. I then googled it an did a face palm :(
In my design on my return system I never thought about putting a stupid hole right under the water level to break the siphon... That is why I have the check valve on there. KISS saved the day again where I can replace a check valve with a hole in my pipe :)

Is there some magic size hole that works best to break the siphon? I would hate to make it too small and have a minor flood during a test or have to drill twice. Lastly, do you have any ideas on the easiest/best way to prime the plumbing? I tend to always over complicate things... hehe


Thanks again!
-Brann

Gary Majchrzak
07/03/2009, 03:24 PM
there's many important reasons for having more water movement at the surface than at the bottom of the aquarium. I helped design many many bottom spray bar type systems in the 90's. I know the rationale behind using them, but TRUST ME.... returns just below the surface of the water is a much better option.

I seem to recall one fella had a really nifty way of priming a pump the way you want but I cannot for the life of me recall all of the critical details right now..... I'm having a senior moment.

Brann
07/03/2009, 03:31 PM
Ok... I will see what I can come up with as far as bringing my return closer to the water. I do currently have a maxi-jet 1200 about an inch under water surface shooting at my overflow to give me surface movement. I designed that in from day one... does that make me any better off?

Also, please let me know if you recall the details on that priming method :)

Brann
07/06/2009, 02:19 PM
So I have tried out that Iwaki pump on my reef tank with my first attempt at the plumbing. The biggiest issue I am having is getting the pipe low enough where it is getting all the water from the sump yet not being lower than the pump braking the siphon. I had it too low at the start and it was chugging out of the return making millions of bubbles :(

One thing I would like to say... This pump does not play around :) It moves a ton of water! So much water that I am wondering if I will have to turn down the flow...

Brann
07/06/2009, 02:26 PM
Success!
Got it pumping full steam... and damn my Overflow box can not even start to keep up :( Looks like I will have to dial back the flow... that thing is hardcore indeed :)


Edit: Tons and tons of micro bubbles :( it looks like this pump is way too powerful for my sump... anyone have any ideas on something I can do with the feed line to cut down on bubbles... Seems I should of designed another bubble trap in the last chamber of the sump...

I know spray bars are so 90's, but I am thinking that is the only way I will be able to use the pump is to reduce the 1" return to 1/2" and pump it through my spray bar. I just need to see how I do with back pressure from cutting it down to 1/2"....


Anyone have ideas? the last chamber of my sump that feeds the pump is 9"x12" if that helps..

Gary Majchrzak
07/06/2009, 03:56 PM
your Iwaki is a pressure rated pump.

you can restrict it's ouput but never restrict the intake of any pump. In order to avoid restricting a pump's output you can build a manifold that recirculates water through the sump (in addition to the return plumbing.) You might also divide returns between your bottom spraybar and the top returns.

The best soultion (IMO) is to increase your drain capacity so that you can run the Iwaki wide open. This might mean using two overflow/drains.

Brann
07/06/2009, 04:15 PM
I am right with you thinking increasing my drain capacity is the way to go :) I just think I need to figure out this whole micro bubble issue. I need to get a 1" to 1/2" reducer to see if running to my spray bar will reduce or get rid of my microbubbles...

Question:
I am wondering if the main source of my bubbles are the unglued PVC joins in my plumbing setup. I did not glue anything yet since I am still trying to figure out how I want to run everything. I have not seen this happen with my smaller pump setups... but could the power of the Iwaki be sucking up air from every little crack in my return line and filling the tank with bubbles?

jdieck
07/06/2009, 04:39 PM
<a href=showthread.php?s=&postid=15313518#post15313518 target=_blank>Originally posted</a> by Brann
Question:
I am wondering if the main source of my bubbles are the unglued PVC joins in my plumbing setup. I did not glue anything yet since I am still trying to figure out how I want to run everything. I have not seen this happen with my smaller pump setups... but could the power of the Iwaki be sucking up air from every little crack in my return line and filling the tank with bubbles?
It well be that the pump is sucking air from the unglued sections on the over the side inlet side. Having said that you may notice microbubbles even if there were no air sucked it trough the conections due to cavitation.
Cavitation is common in centrifugal pumps that have their inlet pressure reduced due to multiple fittings, long inlet piping, reduced inlet diameter or low suction pressure due to lower water level at the input.
Besides the issue of microbubbles, cavitation can damage the pump in a short time due to increased vibration and impingement of the impeller by the bubbles.

Brann
07/06/2009, 08:48 PM
ok... So I glued everything up to make sure that is not the cause. I am letting it dry over night then testing it again... I tried to hook it up to my spray bar and created the largest bubble wand I have ever seen :(

I do not have excessive fittings on my intake and the water comes in through a 1 and 1/2" strainer fitting, so if anything I am over sizing the inlet feed until it reduces to the 1" that the pump needs. If it still fails after all the gluing I guess i will have to try a flex hose for the inlet with no fittings to see if that does it.

I hope the glue does the trick because 1 and 1/4 inch flex is a pain to work work :(

jdieck
07/06/2009, 08:51 PM
<a href=showthread.php?s=&postid=15315159#post15315159 target=_blank>Originally posted</a> by Brann
ok... So I glued everything up to make sure that is not the cause. I am letting it dry over night then testing it again... I tried to hook it up to my spray bar and created the largest bubble wand I have ever seen :(

I do not have excessive fittings on my intake and the water comes in through a 1 and 1/2" strainer fitting, so if anything I am over sizing the inlet feed until it reduces to the 1" that the pump needs. If it still fails after all the gluing I guess i will have to try a flex hose for the inlet with no fittings to see if that does it.

I hope the glue does the trick because 1 and 1/4 inch flex is a pain to work work :(
Just insure the flex hose is not corrugated, otherwise it could create more pressure drop than the fittings.
If that does not work, you may need to drill the sump.

iLLwiLL
07/06/2009, 10:01 PM
I really want to do something similar (minus the spray bar) with an iwaki pump and my un-drilled sump. how are you priming the iwaki initially, and what happens if the power cuts out and back on while you are not home? does the siphon hold?

thanks.

~Will.

Brann
07/07/2009, 09:05 AM
Welcome to the thread Will!

I normally run my system on a battery backup UPS system to avoid that kind of stuff from happening... BUT! I noticed it does not seem to lose its prime if you unplug it. As long as your inlet supply is ABOVE the pump inlet the will pump chug for a few seconds then the siphon kicks in and it goes full blast. Please note that you MUST prime it the first time you run it. But, I only seemed to have to prime it once.

I will have to update my diagram as things have changed a little bit and today I think they will change even more. I attempted to run it without the spray bar by just shooting water out of a elbow towards the overflow and let me tell you... It is powerful! I could not believe the force of the flow it was producing. If I had to compare it to my 1200 maxi jet powerhead it is like the air you can move with a paper hand fan VS a jet engine. It was honestly so powerful it was swirling down to my sand bed from 1 inch under the surface making a mini sandstorm... crazy stuff!

iLLwiLL
07/07/2009, 10:34 AM
Thats great to know it wont need re-priming. but please excuse my ignorance . . . how do you prime it in the first place? I have never used an external pump before, and there kind of intimidating.

Also isn't there some kind of PVC union that will allow water to pass in 1 direction, but not the other? Would that help to keep the siphon better from the sump to the pump?

~Will.

Brann
07/07/2009, 02:00 PM
I will have it all in my diagram once I figure out what the finished plumbing will look like :)

For testing what I did was was T off my return like so it go into the tank and then over it. I put a ball valve above the return into the tank on that T fitting and I just open it then pour water down the ball valve fitting. At the moment I just used the hose from my current pump to send water down that pipe. After the water is flowing back into the sump from the feed inlet for a few second I turn off my priming pump, close the valve and fire up the Iwaki. It is not anywhere near as complex as it might sound :)

Do not worry about the intimidation factor of the pump... I have never messed with one until this project and they are lot less scary than they seem :) It is like any other piece of equipment or tool... respect it and you should be just fine.. I think the only factor to worry about is keeping it dry.

As far as using a one way check valve. I had thought about that when I was designing the system and it turns out you do not need it as far as I can tell for operation. Also, like Gary Majchrzak was saying they can/will fail and I find the best plumbing is the simple kind :)

I just picked up a Diamond Gobey and I'm in the process of acclimating him then the putting him into quarantine. all my glue is dry and I will be taking another crack at the plumbing once the new guy is safely in his tank :)

Gary Majchrzak
07/07/2009, 03:56 PM
not to get offtrack in this thread but Diamond Goby is a notorious jumper- make sure aquarium is covered. I suggest using the garden netting method.

Brann
07/07/2009, 04:38 PM
Glass canopy on my 90gal and I plan to use some of that netting I use to secure my frags to the plugs as a cover for my QT tank :)

Thanks for the concern Gary :)

Brann
07/07/2009, 07:35 PM
Decided to give my plumbing a try since it was all glued up... I screwed in the screw in parts and piped it to my spraybar... BUBBLE WAND CITY!!!! :(

All of my intake is glued and screwed... there is only one unglued part that goes from my return to my spray bar... I guess I will try gluing that tomorrow, but at this point it is not looking very good :(

I really hope it is not a cavitation issue like jdieck was saying... I will glue the last of it and then report back tomorrow.

jdieck
07/07/2009, 10:26 PM
<a href=showthread.php?s=&postid=15321347#post15321347 target=_blank>Originally posted</a> by Brann
Decided to give my plumbing a try since it was all glued up... I screwed in the screw in parts and piped it to my spraybar... BUBBLE WAND CITY!!!! :(

All of my intake is glued and screwed... there is only one unglued part that goes from my return to my spray bar... I guess I will try gluing that tomorrow, but at this point it is not looking very good :(

I really hope it is not a cavitation issue like jdieck was saying... I will glue the last of it and then report back tomorrow.
Well, that is what I was afraid of as it is very common to get cavitation with an over the side installation.
Once you glue the last piece, if you still get bubbles try this test.
Start slowly closing the valve at the pump outlet, the noise of the pump will become a higher pitch and more ssteady and the bubbles should disapear as you reduce the flow. If the bubbles disapear then it is cavitation and the alternative will be drilling the side of the sump.

Brann
07/10/2009, 02:32 PM
<a href=showthread.php?s=&postid=15322252#post15322252 target=_blank>Originally posted</a> by jdieck
Well, that is what I was afraid of as it is very common to get cavitation with an over the side installation.
Once you glue the last piece, if you still get bubbles try this test.
Start slowly closing the valve at the pump outlet, the noise of the pump will become a higher pitch and more ssteady and the bubbles should disapear as you reduce the flow. If the bubbles disapear then it is cavitation and the alternative will be drilling the side of the sump.


Ok here is the update...

I did the test jdieck told me about and with my PVC feed line into the pump I did indeed have a cavitation issue. I had to restrict the flow to the point where it was almost off :(

So, I went to the hardware store and got a 1" to 1 1/4" hose barb elbow. I scrapped my PVC return and hooked up the elbow with some braided hoses that was 1 1/4" which is 1/4" over sized for the return of the pump. It started bubbling up again which made me kind of sad. I then said what the hell... I hooked it up to my spray bar and tested it again very slowly to try the cavitation test with the hose. I started with the valve almost all the way closed and slowly opened it up... The bubbles went away!!! :)

I guess I just needed to start slowly and work the air out of the system on this hose setup. I then slowly opened the valve more and more... I am at the point where the return flow is faster than my overflow can handle and if I turn it up anymore I will over flow the tank :)

The only issue is the pump is a little bit loud. My tank is in my computer server room and it sounds about as loud as one of my servers. The noise does not bother me too much, but I am wondering if this is going to damage the pump. I am looking into getting a 2nd overflow box to run the pump full blast and for the extra security if one box loses siphon :)

Right now the 1" return goes in my 1/2" spray bar which is about 80% open.

I am waiting until I get my 2nd over flow box in to finalize my plumbing... Feel free to ask any questions and give me any input.

Gary Majchrzak
07/10/2009, 02:42 PM
dampen pump noise by placing it on a PC mouse pad or two ;)

Brann
07/10/2009, 02:56 PM
Good thinking I will give that a try :)

Thanks for the help btw Gary and jdieck I know my little project is not finished, but thanks to you guys I did manage to skip a bunch of trial and error :)



Here is a little pic of my fish checking out the new flow in the tank... they seem to be back to normal at this point :)
http://farm3.static.flickr.com/2488/3708233682_a070b13200.jpg

jdieck
07/10/2009, 03:01 PM
<a href=showthread.php?s=&postid=15337722#post15337722 target=_blank>Originally posted</a> by Brann
Good thinking I will give that a try :)

Thanks for the help btw Gary and jdieck I know my little project is not finished, but thanks to you guys I did manage to skip a bunch of trial and error :)



Here is a little pic of my fish checking out the new flow in the tank... they seem to be back to normal at this point :)
http://farm3.static.flickr.com/2488/3708233682_a070b13200.jpg
Glad it is working just keep a close eye on it and get prepared as the pump can easily loose priming specially with the larger inlet.

Brann
07/10/2009, 03:09 PM
Honestly, It seems to be VERY good at holding a prime at this point. I hope I did not just jinx myself :)

I can turn it off then wait 24 hours and it will start right back up. I have to blow into the pipe to force all the water out if I want to break the siphon. Fingers crossed that it stays that way! I just need to look into an auto top off for the sump, so the water never dropped lower than the feed hose.

Brann
07/10/2009, 09:16 PM
***Sorry in advance for spelling, typing, grammar, ect***


Disaster strikes because I am a TOTAL @#*@#$*#$&% MORON!!!!!

I switched over to the new plumbing like I said to test it out... I went away from it for like an hour... I put off drilling the anti-siphon hole until after my break since I would have to drain some water from the display tank to do it....

Can you guess what happened next???

LIKE A COMPETE AND UTTER IDIOT!!!! I accidentally put the Iwaki pump on a the same power strip as my lights and when the timer went off so did the pump!!!!

It drained my 90 gallon just about all the way to the sand bed because I was too much of a fool to either A. Drill a single hole or B. Put one of my many check valves into the loop.

I opened the basement door and saw the carpet was soaked as far as the eye can see... Now I have had spills, but nothing 80ish+ gallons since the seam on my 220gal tank failed last year... I have a good system in place to combat flooding, but it still sucks hardcore when it happens...

My fish were flopping around on the sand bed... all my coral was out of water... If I had not come down until the morning my tank would of been 100% dead :(
Most of the water is picked up and I am just waiting for the wet dry vac to cool down before going after the carpet.

Thankfully MOST of my fish are accounted for... I see my two clown, 1 chromis, my little puffer and my yellow tang. That only makes 1 chromis and my mimic tank on the missing list. I REALLY hope they made it to a puddle and are just hiding out in the rocks. What really saved me was 15 gallons off saltwater mix in a barrel and sucking all the water from my 55gal sump and into to my 90gal which JUST covers all the coral and rock work.

I guess there is not much else I can do other than just wait until morning, clean the water mess and really hope that my two missing fish are just hiding.

I assume if they had dried out and died they would be floating right? My worse fear is they died a horrible death wedged inside the rock work... I AM SUCH A MORON!!!!


In closing.... NEVER put off safety features that will keep you, your fish and your house safe... You do not want to end up being a moron like me :(

iLLwiLL
07/10/2009, 09:54 PM
oh noes, you totally jinxed your self!!

that really sucks, but at least you were able to save the majority of the live stock. I thought I had a bad day of plumbing when my iwaki blew an un-glued 45* elbow when i was testing it putting around 10 gallons of water behind my stand in like 15 seconds. cant imagine what it would have been like if I wasn't there for an hour. sooo glad I made the extra trip today to get that check valve.

i told you external pumps were scary!! :D

~Will.

jdieck
07/10/2009, 10:25 PM
Sorry for what happened. Wish you good luck.

Brann
07/11/2009, 10:08 AM
<a href=showthread.php?s=&postid=15339652#post15339652 target=_blank>Originally posted</a> by iLLwiLL
oh noes, you totally jinxed your self!!

that really sucks, but at least you were able to save the majority of the live stock. I thought I had a bad day of plumbing when my iwaki blew an un-glued 45* elbow when i was testing it putting around 10 gallons of water behind my stand in like 15 seconds. cant imagine what it would have been like if I wasn't there for an hour. sooo glad I made the extra trip today to get that check valve.

i told you external pumps were scary!! :D

~Will.


Honestly I can not blame the external pump in the least since it was 110% operator error. It was working fine until the timer shut it off and reversed the siphon... That could happen with a little cheap $10 pump :( I have since started the recovery effort to save my tank and drilled the anti-siphon holes in my return pipe that I should of done before....


Here is what I know so far:

I stabilized the system as best I could with the water I had available. My fuge and display tank rock work is JUST covered up with water. I put the RO filter on my 30 gallon barrel and went to sleep since there was not much else I could do.


I woke up and confirmed that my missing Chromis and Mimic Tang are alive!!! Dodged a bullet on that one :)

However there seems to be some o2 issues with the water or the fish are VERY upset as they are breathing VERY quickly and my little puffer was gasping for air at the surface of the water. I have put a maxi-jet 1200 powerhead right under the surface of the water to break the surface and exchange gases. In a rush I added too much salt to my 30gal of water and I am waiting for the RO to bring it down to where I need it.

I am still another 6 hours or so of RO water away from getting enough water in my sump to start my pumps back up and get my system running again :(
Is there anything I can do until then to better exchange the gases and get more o2 into the water for the fish?

Brann
07/11/2009, 07:00 PM
****UPDATE****


All the fish have made it! My puffer was laying on the bottom and had me worried for like 4 hours, but he just started swimming again on his own. They just all ate which I am taking as a good sign.

My coral seems to mostly be intact... I have one cluster of green stars that has not opened up yet. It was on the highest point of my tank and dry the longest... With some luck it just needs a day or so and the mat will not die off.

I have tested my anti-siphon hole and get what... It worked :) 1 little freaking hole the size of a spaghetti would of stopped this whole disaster... I am VERY humbled and feel more than a lot stupid...


The Iwaki is pumping away like nothing ever happened and I did not even need to re-prime it. I plugged it back in and after 2~3 seconds of bubbles it was flowing like a champ.

jdieck
07/11/2009, 09:20 PM
Just test that the pump will not loose priming if you shut it off now that you have the anti-syphon hole.

Brann
07/11/2009, 09:38 PM
Sorry I forgot to explain that I did a full power failure test with the ant-siphon hole. It drained until it hit the hole and stopped ;) I waited about 3mins then turned it back on... restarts fine :)