How to do water changes from the sump?

[Sordfish]

I am relatively new to sumps. My previous tanks have all been canisters. I had set up a semi-automatic water change system where I had a small drain pump permanently in the display to drain the tank, and a small pump in the salt water tank to refill it through a hose that also stayed in the display tank permanently. Not very slightly but made water changes as simple as turning on and off two pumps. Now that I have a sump, I’d like to put the drain pump in the sump, and have the hose from the salt water tank to end in the sump. This should look a lot better. However, the volume of the sump is 25 gallons and the tank is 120. So I’d not be able to do water changes larger than 15% of the total volume. Any thoughts on how to do larger water changes through the sump?

 

[ATB USA]

Do more small changes

 

[Sordfish]

Do more small changes

Thanks. Small changes are what I usually do but sometimes you need to do larger water changes to get proper dilution of nutrients or chemicals. For example, there are emergencies where you need a large water change ASAP. In other situations, you may be able to wait but doing small water changes to get a large dilution can be wasteful. For example, to get 40% dilution, you’d have to do 7% daily changes over the course of a week resulting in a 50% water change in total. This is wasteful since you are using 25% more water (50%) in comparison to the dilution you achieve (40%). So for these situations I wanted to see if people have a clever solution of how to do a large (25% or more) from the sump - this site is full of creative people. I am just setting up my plumbing so I want to set up a system that will work for all situations.

 

[mike550]

@Sordfish my tank and sump are around the same size. For your regular water changes you could do what you’re describing. I do something similar when I want to clean my sump.

As for big water changes (which hopefully don’t happen too often) you’re probably most efficient by removing and replacing water from your DT. The size of your sump will limit the exchange.

It sounds like you’re describing an auto water change system. If you take water out from where it enters your sump and add back at the return pump then presumably your exchange could be infinite.

 

[Joekovar]

If you can hide a small utility pump inside the display, you can use that to bring more water into the sump after you've drained the sump.

 

[tsouth]

Let’s use a 100 gallon tank as an example
Turn off the skimmer and top off

Fill five 5 gallon buckets of new water
Pour one bucket of new water into your sump
siphon one bucket of old water from your display on the opposite side of your return
Let your water level itself back out

Do this for the other four buckets

Try this instead of coordinating pumps

 

[Quietman]

If you have to do more than 15% water change at one time, you're probably dealing with an urgent situation and the appearance of a pump or hose temporarily in the DT will likely be least of your issues.

The only ways to remove more water safely from the sump is either a bigger sump or a reservoir of water that also accesses the sump with flow through it or an auto water change system. A DT pump to bring water down to the sump to change water is an accident waiting to happen. Same for putting a hard piping a connection lower in the DT. Sure you can do it, but it only takes once to drain your tank on the floor.

Without setting up an auto water change that adds and subtracts without need to shut off return or doing a few 15% in sequence - which is what you would probably do in emergency- I wouldn't add uncontrolled or "accidentally left on" flow from DT.

Also...trying to economize on water changes improving by some small percentage probably isn't worth the risk especially if you're diluting for corrective issue. Last point...huge water changes are very disruptive to the livestock.

 

[Sordfish]

Thanks everyone for your input. Very helpful so far.

Perhaps a little more context would be helpful. I am consolidating all my tanks into two larger tanks- I no longer have the bandwidth for more. One is a Red Sea peninsula 500, which will be my sole reef tank. The other is a Red Sea 250, which will be my sole high tech planted tank. I bought them used and am selling my existing tanks to finance them. I was hoping to set up the same water change plumbing for both, but based on your answers, I may have to rethink that based on your inputs - for high tech planted tanks, weekly 50% water changes are a minimum. One reason for wanting a cleaner DT is that these will be in the living room and rec room, so ability to bring in hoses and access to bathrooms is limited. So I want to set up plumbing from the basement to enable me to do the water changes without having to haul buckets.

@mike550 said:
It sounds like you’re describing an auto water change system. If you take water out from where it enters your sump and add back at the return pump then presumably your exchange could be infinite.

I hadn’t thought of this. I think you are talking about something like Neptune DOS. Perhaps for the saltwater tank I can use this where I do 2-3% changes per day. For emergency large changes, I suppose I can run the DOS until the sump empties, then refill the sump, and then empty it again and so on. Bit cumbersome and inefficient but at least doable. I wonder how quick these pumps are - I.e. would it be feasible to do a 30% water change in a reasonable amount of time?

@Joekovar said:

If you can hide a small utility pump inside the display, you can use that to bring more water into the sump after you've drained the sump.

Cool idea, but I’d have to think about how to make it idiot proof so that I don’t overflow the sump by mistake, which as @Quietman suggests is a real possibility.

@tsouth said:
Fill five 5 gallon buckets of new water

Unfortunately not a real option. The reason is, carrying buckets from the basement will quickly get old, and I know from experience I’ll start skipping water changes and then everything will go downhill. One of the main reasons why I am trying to do the water change plumbing is I always loose when I go against my own nature .

@Quietman said:

Without setting up an auto water change that adds and subtracts without need to shut off return or doing a few 15% in sequence - which is what you would probably do in emergency- I wouldn't add uncontrolled or "accidentally left on" flow from DT.

You hit it right on the none re my main concern with even the pump from the salt water (or remineralized RODI in the case of planted) to the sump. All it takes is a few minutes of distraction. And frankly my wife would kill me if I flooded the living room with salt water. So perhaps I should look into level sensors to shut off the pumps as a further insurance. It’ll be a bit of a challenge since my water station is 25 feet away and a floor below the tanks. I’ll have to think about how to communicate from the sensor in the display tank to the pump in the salt water tank. Any suggestions would be appreciated.

 

[mike550]

@Sordfish Ive heard mixed reviews on DOS water changes. Looking at their specs the max you could move is 4 gph. There is the AutoAqua AWC which rates at 74gph. It’s also an ATO which makes it more interesting. Some places say the AutoAqua is discontinued . But maybe there’s a model change in the works. Idk

 

[MarshallB]

@Sordfish Ive heard mixed reviews on DOS water changes. Looking at their specs the max you could move is 4 gph. There is the AutoAqua AWC which rates at 74gph. It’s also an ATO which makes it more interesting. Some places say the AutoAqua is discontinued . But maybe there’s a model change in the works. Idk

Yeah the DOS is more for continual water changes. You also have to put the dos head somewhere where you wont hear it is extremely loud when running at full blast. I don't do continual water changes. I just have it turn on at 2 am and change out 1.5 gallons and done. If I were to do 2-3 gallons throughout 24 hours it wouldn't be loud, but if you tried to do 30 gallons... yeah..

That said its been very reliable and i like having the ability to adjust and monitor it on the fly.

 

[mdb_talon]

Not sure if this helps, but when i do a WC i always drain from sump, however i want to suck detritus from rocks and the low flow spots on bottom of DT. So i just have a small siphon hose that i clamp so it drains into my sock in sump. So that way my waste drain is just in the sump but i can clean the DT also and fo a larger volume change. I personally dont just do small water changes i prefer 20-30%

 

[mike550]

@mdb_talon I don’t have a layout where AWC would make sense. So I’m old school python in the DT to clean things up and then refill fresh SW through a pump connected back to the python.

 

[Sordfish]

Not sure if this helps, but when i do a WC i always drain from sump, however i want to suck detritus from rocks and the low flow spots on bottom of DT. So i just have a small siphon hose that i clamp so it drains into my sock in sump. So that way my waste drain is just in the sump but i can clean the DT also and fo a larger volume change. I personally dont just do small water changes i prefer 20-30%

I like that idea a lot. Thanks. I’ll see what I can design.

 

[Sordfish]

Yeah the DOS is more for continual water changes. You also have to put the dos head somewhere where you wont hear it is extremely loud when running at full blast. I don't do continual water changes. I just have it turn on at 2 am and change out 1.5 gallons and done. If I were to do 2-3 gallons throughout 24 hours it wouldn't be loud, but if you tried to do 30 gallons... yeah..

That said its been very reliable and i like having the ability to adjust and monitor it on the fly.

Good to hear. I think I’ll set up a DOS for daily changes and use the siphon idea of @mdb_talon with a drain pump in the sump for large changes/ DT clean.