Water Pressure & PC watts

[DHS]

Yes I'm back with even more questions (figured my next tank I'd setup perfectly for once).
1) With a water pump from the sump is there a quick conversion from 0ft. pressure to say 4ft pressure so that I can make sure I'm getting a strong enough pump?
2) I currently have a 23 watt PC lighting over my 20g tall tank. I've read all about different types of lighting and how many watts per gallon one needs, but I've never seen what the PC watt is compatiable too. I just want to make sure that I get enough lighting for my new tank (40 Gal). I'm think of using my 23 watt PC and a 175 watt MH...or if I can find another PC to take its place since they are relitivity cheaper.

Thanks in advance,
DHS

 

[Anemoneman]

On the manufacturer's web site you should be able to get pump curves that show the decreasing output vs. head for your pump. It is different for different pumps, depending on the pump design. There may be a rule of thump out there? Basically if you size your pump for at least 10 times your tank volume per hour, you should be safe for up to 4' of head without having to do the math. example: 40 gallon tank - use at least 400 gph pump.

One 175 or 250W MH over a 40 breeder will be fine. The 23W PC won't do much unless you want to supplement the MH with actinic.

Mark

 

[loganj]

As Mark said, you'll have to go to the website or look on the box to find the flow chart for the pump. I have noticed that the smaller pumps will lose a good portion of their flow in the first 4-5' while the larger pumps may not experience a loss until 6' or so. Also, add 1' of height for each 90 deg elbow that is in the plumbing on the pressure side of the pump. IE...if you have a 4' rise with 2 elbows in it, figure for 6' of head total. Remember that the 10x is minimum...you can go more without hurting anything...I have about 250gph in my 10 gal. Include PH's in the equation when you figure the total flow.
As far as the lights go, maybe use the MH and add another 23w PC...use the PC's for actinic? I'm not sure how long a 23w PC is, but I don't think you'll get good coverage on a 40g with just one.
Logan J

 

[DHS]

Well I thank everyone for the info on the lights....though I really was more interested in the info for the water pump. So by unpopular demand I give you a site that has the information:
Rio Flow Chart
ViaAqua Flow Chart
If anyone ever needs the info here it is for use.

PEACE,
DHS

 

[reefrunner69]

The problem is figuring head pressure...it is not simply how high is the tank compared to where the pump is. There is frictional loss, there is gravity etc...To figure your head pressure accurately...there is a calculator for it on Reef Central. We appreciate the links...but I don't use either of those pumps, some may, but lot's won't. That is why it was suggested that you consult the manufacturer's literature. The flow chart for a Rio 2500 will not be the same as for a Mag 7, although they are comparable pumps.

 

[loganj]

What kind of pump were you thinking about using? External or submersible? IMHO, the Danner Magdrives are excellent submersibles although they can be run external also. The only externals I have any experience with are the Little Giants and the Hydrothruster. The Hydrothruster is old and the impeller locks down occasionally due to (I think) a worn shaft. The Little Giant has never given a problem. I think fishfreek also uses Little Giants on his reef. I'm not a big fan of the Rio pumps because I have had trouble with their power heads in the past. I don't know anything about Via Aqua.
Logan J

 

[DHS]

I'm thinking I want to go with submersible, but either would work since I'm going to be building my own sump. I mostly need something that can hold a GPH of 400-450 for 5 ft (not that I'm pushing the water that high just better safe then sorry). I also don't have the $100+ dollars I've been seeing for some of the pumps (even eBay is expensive), so I'm also looking for a pump in the range of $1-$75...big range huh.

PEACE,
DHS

 

[SW Beginner]

These links should help some (though I am not sure how much):

Pumps
Friction loss, etc.

 

[DHS]

SW that second link is just the best I've ever seen. Finally my questions are answered...and the spread sheet on the page makes all of it make sense. THANK YOU THANK YOU THANK YOU....sorry just excited to get a truely scientific answer instead of opinions. In fact it helped me decide that I'm going to get the Rio 2500 instead of a Mag7. Not only does it get better flow rate for the same amount of watts, but its also $15 cheaper.

Thanks again SW.

PEACE,
DHS

 

[SW Beginner]

You're very welcome! Still, for a $15 difference would get the Mag 7 over the Rio as it will, in all likelyhood, prove to be more reliable in the long run.

 

[DHS]

Well the money is of little difference I also looked at the difference in outlet. The Mag7 only gives a 0.5" outlet where as the Rio give a 0.75" outlet. Now that may not sound like a big diffence to some but to me that makes a big difference since I need the outlet to be hooked up to a 1" tube to set up my flow box (old power filter with the motor removed). And as for the long run....I only need it to get me through 2 years with my 40 gal tank till I get my house and get to install a 200+ gal tank with all the bells and whistles...heehee

PEACE,
DHS

 

[loganj]

Well...it's your choice of course. All I can say is that it's about as easy to go from 1/2" to 1" as it is to go from 3/4" to 1". I've just heard too many bad things about the Rios I guess.
Logan J

 

[reefrunner69]

Rio has an out let of 1/2" as well, Rio also has the largest catastrophic fail rate of any submersible on the market. Mag 7 will overtake the rio in flow as the head pressure builds, mag 7 will pump to a higher head pressure than rio will. All that said, I knnow lots of people that have had good luck with rios, but more that have had bad luck.

 

[michealprater]

Personally, Every Rio pump I have ever had has burned up. Thats just my personal experience. I would just feel bad if I didnt warn someone about them.

 

[Anemoneman]

I'm going to get the Rio 2500 instead of a Mag7. Not only does it get better flow rate for the same amount of watts, but its also $15 cheaper

I hope I post this in time. You don't want a RIO as your main pump! To put is as tactfully as I can - RIO pumps suck. You get what you pay for with these. There's a reason they're cheaper. They are noisy, fail to restart after a power out, retain air (cavitate). The Mag7 is a quality unit. Very high output and quiet. It can be used external or submerged.
If you really want a RIO, use it for water circulation only. That way when it quits it won'thurt anything. And when it doesn't want to restart after cleaning, you aren't depending on it.

 

[DHS]

Ok guys I get the picture...no RIO, and since the tax man comith I can get the Mag 7 with no problems...(hmmm may get the Mag 9.5 ). Though one question comes to mind...if any "bugs" get sucked up through the mag how badly will they get chopped up ?!? I'm hopeing to hear the answer of None/Very Little.

Peace,
DHS

 

[reefrunner69]

Mag pumps come with a foam prefilter, if your willing to clean it often, no bugs will get sucked up. If you don't use the prefilter...they will get chopped up no worse than other pumps. I suspect quite a bit of pods make it though the pumps and plumbing, just fine.