New here and first saltwater tank

Gary Mason

New Member
So, I am getting ready to set up my first saltwater tank. I bought my Brother-in-law's 125 gallon tank, stand and hood. He is giving me his octopus 150 protein skimmer, but I am pretty much on my own for the rest.

I will have a 20 gallon tank as a sump, will install baffles, but wonder how many GPH I will need through the filter for a FOWLR tank. My intention is to install a couple power heads for some wave action, but just not sure how many times per hour I need to turn the water over. I've heard anywhere from 5X to 20....and and just totally confused.

Don't have it at home yet, but will be picking it up next weekend.

TIA!
 

geridoc

Well-Known Member
Ask 10 people and you will get 10 different answers, but all will be in the range of 5-20 times the volume. That said, I try to get about 10 x vols, but oversize the pump, then use a ball valve to throttle the flow to what I need.
 

Gary Mason

New Member
Ask 10 people and you will get 10 different answers, but all will be in the range of 5-20 times the volume. That said, I try to get about 10 x vols, but oversize the pump, then use a ball valve to throttle the flow to what I need.
I'm curious why oversize the pump and then throttle it back? AS I am researching, the bigger the pump the more expensive so there must be a reason for that. Not being snarky, truly curious why.
 

geridoc

Well-Known Member
I suggested an oversized pump with a ball valve for several reasons. First, your calculations may not take into account the head loss, so the actual output of the pump may be lower than you expect, and if it is, you can open the valve. Second, output falls off over time, and as it does you can, again, open the valve. The cost differential fora larger pump should not be too great - you don't need a hugely larger pump, just the next size up will usually work. There are pros and cons to the inline vs. submerged issue. Inline pumps transfer less heat to the water, reducing the possibility that your tank will run too warm (I have that issue with my 220 system, and have to use a chiller). OTOH, inlines are noisier, even if you use vibration-deadening padding. Submerged pumps heat the water, and can be a major PITA to service. The best solution, IMHO, is what I am currently working on - I am moving my sump from below the tank on the first floor of my house into the basement, where I will use a large (Hammerhead) return pump inline. Since the pump will be in the basement I won't worry about noise, and I expect to do away with the chiller (and the cost of running it).
 

Gary Mason

New Member
I suggested an oversized pump with a ball valve for several reasons. First, your calculations may not take into account the head loss, so the actual output of the pump may be lower than you expect, and if it is, you can open the valve. Second, output falls off over time, and as it does you can, again, open the valve. The cost differential fora larger pump should not be too great - you don't need a hugely larger pump, just the next size up will usually work. There are pros and cons to the inline vs. submerged issue. Inline pumps transfer less heat to the water, reducing the possibility that your tank will run too warm (I have that issue with my 220 system, and have to use a chiller). OTOH, inlines are noisier, even if you use vibration-deadening padding. Submerged pumps heat the water, and can be a major PITA to service. The best solution, IMHO, is what I am currently working on - I am moving my sump from below the tank on the first floor of my house into the basement, where I will use a large (Hammerhead) return pump inline. Since the pump will be in the basement I won't worry about noise, and I expect to do away with the chiller (and the cost of running it).

WOW...excellent response! Thank you!

SO I get the over rating the pump...perfect explanation and it makes perfect sense.

As I understand the difference between submerged and inline, there are pros/cons to each and it is a trade off when deciding. Since I will have my tank in the basement, I do not have the option of moving the sump down a floor, so will likely choose a sumbersible pump, and will watch the heat transfer. Since I will likely need a heater, will the heat form the pump offset that need slightly, or would the heat transfer exceed what the heater may provide...in other words, perhaps I would not NEED a heater?

Sorry if I am asking dumb questions, I really am new to saltwater and don't want to kill off a bunch of expensive fish, or get discouraged because of simple mistakes, so I appreciate the help!
 

geridoc

Well-Known Member
If you are running a single submerged pump you probably will want an auxiliary heater. If you are running several pumps (skimmer, return, algae scrubber, even a chiller in my system) you might need a chiller rather than a heater. Basements are frequently cooler, so you might be able to power-ventilate the sump with a small fan to control overheating.
 

Gary Mason

New Member
Sounds lik I wll just have to start slow, and monitor temperature closely before adding fish to make sure i have everything stable...thanks for allthe help!
 
Top