Help Sizing Return Pump

Hello all!

I need help sizing my return pump.

I have a 110 deep blue tank that is reef ready (starting to regret that decision)

The water entering my sump comes down 1-1/4" pipe reduces down to 1" entering the bulk head and exits into 3/4" pipe into my sump. I have a ball valve to control flow.

My return line to the DT consists of 2 unions, a 90, a check valve and 2-45's. With about 4.5 feet up to the top.

Lately my water level in the tank is the same level as the return corner area. I opened the ball valve all the way and it lowered the water level in the corner. So there is now a waterfall going over the baffles (wife is not happy with the sound). It is also starting to lower the DT level which leads me to believe my return pump is too small.

So I dial down the ball valve and the water slowly rises.

I had no sound before and the water levels in the two areas were the same.. Creating the next problem.... Surface scum!

Please help!!!

 

What kind of standpipes do you have in your overflows. Mine look like this and there is a breathe hole on the top that sometimes gets clogged causing them to have flow changes until I clean the breathe hole. This set up is the quietest set up I've seen so far. Always reliable no issues in over 8 years with them. The drain line is the same size all the way to the sump also. No restrictions. On the return side I have too much and need to upgrade the pump though. I think if you plumb your drain with all the same size plumbing and use the durso style stand pipe you might be ok. Depending on the pump you have.

 

First, get rid of the ball valve on the overflow, never restrict the overflow! It is the return pump that regulates the flow not the overflow so leave it wide open undisturbed. I would also increase the size of the overflow plumbing below the bulkhead to the 1" to reduce headloss since this is a gravity system and every little bit adds up.

On the return side eliminate the check valves, they will lead to a flood and are a false sense of security that will fail almost guaranteed. Plus the add headloss and reduce the flow of the pump signifciantly.

As long as you keep the returns close to the surface only a minimal, very easily calculated amount of water will backflow until the returns are exposed to atmosphere and the siphon breaks. An air gap is the best, most maintenance free, foolproof method of backflow prevention known to man, we all know water cannot jump uphill so they can't be defeated. Keep a little freeboard or extra room in the sump and you will never have a flood and don't have to maintain any drilled holes or check valves that will fail anyway, Murphy's Law.

I have been using the Stockman DIY standpipe for 9 years now with zero issues. Very quiet and flows like a beast with little possibility of plugging.

 

This will be the 3rd time i've plumbed this system if I change. The bulk heads that came with the tank I took into home depot and lowes and couldn't find anything that would fit inside them under the tank. It goes from 1-1/4" down to 1" through the bulk head. I have a 3/4" coupling under the tank which then fits into the bulk head. A 1" pipe wont fit into the bulk head but the O/D of the 3/4" coupling will. I have it glued with ABS cement. This was the only thing home depot had in order to get this thing up and running. I found schedule 80 bulk heads online but from what I was reading they are larger then ABS and I would run the chance of them not fitting in the pre-drilled holes in the tank.

Any recommendations on how to get a 1" pipe attached to my ABS bulk head?

As for the check valve. I have that in there because over the winter I spent a lot of money on hardwood floors in my living room. I am freaked out something bad will happen. My return into the tank is loc line and I keep it about 2" under the water. If I don't put it that far down I get a little cyclone that forms and then ends up breaking into tiny micro bubbles. Also, I cut the power to the pump and since the loc line is 2" under the water, 2" of water siphoned into the sump. So I wanted to avoid this so I put the check valve in.

I really wish I would have gone with a non drilled tank and just had a HOB overflow box.

 

My pipes look like this. Different colors but the same layout. It is what came with the tank. The hole isn't plugged and the noise is coming from the overflow from the tank to the corner compartment that these pipes are in. The noise isn't coming from the water going down the pipes.

 

Could those be metric slip bulkheads? I have never heard of standard size PVC not fitting inside a bulkhead. This is another reason I only use thread x thread bulkheads, nothing gets glued and they can be easily removed or modified in the future. I have a Bulkhead Installation Tips sticky thread here on 3Reef somewhere that goes into great detail.

Do not depend on the check valves, I am telling you from 38 years experience in water and wastewater operations and maintenance, they are a false comfort and can and will fail when you least expect it. I spent thousands on new hardwood floors and porcelain tile myself and would never think about installing a check valve as I know for a fact all it does if give you a warm fuzzy feeling. No matter how much maintenance you do on them, clean them, execrise them etc, they are going to fail. It does not have to be a catastrophic failure either. A grain of sand or piece of food or algae on the valve seat or a slime or calcium build up which is going to be present or any number of things can and will defeat them.
Design the returns and sump properly and you can sleep soundly at night with no fears or worries, a flood cannot happen with an air gap. I have seen way too many check valves and drilled holes fail over the last 30+ years in the hobby to be comfortable myself.

Not sure how you have your LocLines but I use two 3/4" Loc Lines on a WaterBlaster HY-5000 pump running wide open with less than 4 feet of total head on it and 3/4" below the surface is quiet as a whisper? How do you have them pointed and what nozzles do you have on the Loc Lines?

Just trying to help here so you can take the friendly advice or not but I think others may chime in here also. It is so much easier to do it right the first time rather than having to go back and redo it, been there, done that and never want to again if possible.

 

Here you go, if you want to get really precise. Use the equations interchangeably based on which variables are known, setting equations equal to each other in order to solve the unknowns. Ultimately getting pump horse power, which can then be converted to watts if its a smaller pump.
Pump Design Equations Formulas Calculator Water Horsepower

You could also look up the equations involving a Reynolds number, which is how I was taught and is very accurate, but it is endlessly more complicated than the ones that website gives. Out of 15 people and 2 pump sizing problems, not one person got even close to the right pump size using the Reynolds number method.

 

It could be a metric bulk head. Like I said I took it into the hardware stores and they were clueless as to what it even was. At first, I thought an adapter screwed on the threads but it doesn't. So I figured a 1" pipe would fit inside the threaded side but it didn't. The guy helping me happened to pick up a 3/4" coupler and that fit so that is why we dropped it down to 3/4".

When I get off work and get back from getting live rock ill post some pictures of my set up so you can see what i'm talking about. Explaining stuff without seeing is difficult, IMO. I don't have an adapter at the end of the loc line, maybe that is why a cyclone wants to form. I bought one but it was too small and I never made it back to the place I got it from.

I'm sick of plumbing so i'm hoping this time will the the last time! It's getting frustrating.

 

Ideally you want your overflow to have the same size piping but that is going to be up to you whether you change it or not. A fan nozzle on the loc line will help with the cyclone you talked about so you can set the loc line closer to the surface and take out the check valve. As for the waterfall sound. It sounds to me, like you suspected, that you need a stronger return pump. With a stronger pump that you can adjust, you can adjust the return flow so that you have a quieter flow in to the overflow. It is all about matching your return to your overflow, not vice versa.

 

Sounds like your standpipes are not tall enough if you are getting water crashing sounds over the wier or teeth. Normally you can fine tune an overflows noise with a piece of airline tubing stuck down in the drilled airhole in the standpipe cap and adjusted up or down until it queits down and flows best but that does not sound like your issue.

Most people, myself included, will tell you 3 to 5x the display volume is a good size for a return pump. I err on the larger side so in your case maybe 5x110 or probably 600 GPH after headloss. No more than maybe 700-750 and adjust the flow with an inline valve on the discharge side of the pump.