Hobby RO Pump Suggestion

[vordus]

I am in the process of setting up a "Hobby" RO and plan to use 2 or 3 400gpd membranes. I was wondering what pumps you guys are running. I called Aquatec and talked about the 8852-2P01-T421 160 PSI, 3/8 JG, 24 VAC. The Sales person suggested possibly going with a 5858-2LM2-B534 130psi. Any help would be appreciated.

[BartzFarm]

I know it's been nearly 6 years since this post but I was surprised that this was all that came up in my search for the 5858-2LM2-B534. I just built my first RO with this pump and was very pleased with it. I ran it at 110psi pulling 2.8amps through two 400gpd membrane. I was getting 50/50 concentrate to permeate with the concentration flowing at 4 gallons per/hour. The pump stayed at 100 Deg F. and barely broke out into a sweet.

[DRoseum]

Coronwater TYP-8900K if you want to go with more than 2 x 400 GPD membranes.

[fireant911]

Hey Dan,
My apologies for always ‘piggybacking’ on others questions to ask another question BUT it is somewhat related. In regards to the Coronwater TYP-8900K pump, can 600 gpd RO membranes be effectively employed with this pump? I saw your 2023 build incorporated five 500 gpd RO membranes in series - have you attempted anything with 600 gpd day membranes with that pump?

[BartzFarm]

Coronwater TYP-8900K if you want to go with more than 2 x 400 GPD membranes.

Thanks Dan, I'm happy to see you respond to my newbie post. I've been studying and working on your design for over a month. I attempted to purchase the Coronwater TYP-8900K twice, thru Amazon and pwangroup.net, but got scammed both times. Yes, I know I should have purchased it thru AliExpress but didn't have time to wait for delivery. Sap started flowing very early in Ohio! This is only my 3rd year of tapping. Last year I built a two pan & barrel evaporator. This year I built your RO system with only two membranes; my budget is very limited. Next year I'll expand the RO but now I'm wondering if this pump can handle it.

Before I start putting more money into this pump, like upgrading the transformer, adding a temperature limit switch and installing a fuse, perhaps you could teach me why the Coronowater 8900K is that much better? If I were to add more membranes wouldn’t that increase my output and cause less stress on the pump? Also, forgive my ignorance, but on your diagram, where does the 2.6 lpm come from? Oh, and if an 800 GPD pump is better then why not get a 1200 GPD pump for the same price? Like the Germany Seiko Global 1200 (Shenzhen Huashun Baier Electric Co., Ltd.)

On another note, perhaps someone can tell me if it’s ok to leave a 1% hydrogen peroxide in my system between runs, once/week and wait to flush before use. Again, I have a limited budget and can get plenty of H2O2 for free. I’m just confused about the cleaning process between runs.

Thanks for your response and any advice is greatly appreciated!

[DRoseum]

Hey Dan,
My apologies for always ‘piggybacking’ on others questions to ask another question BUT it is somewhat related. In regards to the Coronwater TYP-8900K pump, can 600 gpd RO membranes be effectively employed with this pump? I saw your 2023 build incorporated five 500 gpd RO membranes in series - have you attempted anything with 600 gpd day membranes with that pump?

Yes I am using a 600 gpd membrane in each of my units with 5 membranes in series. 600, then 4 x 500. Works great.

[DRoseum]

I am not familiar with the pump you mentioned or all of its technical specifications. Will need to do some research on it. The coronwater 8900 is one of the highest flowrate diaphragm booster pumps that has a continuous duty cycle.

As for BOTH the aquatec 5858 (or any 5800 series), and the 5300 series, the problem is the heat rise. You cannot run these pumps for more than 60 or 70 minutes at 100 psi or higher without them shutting off due to thermal limits.

The coronwater 8900k can run indefinitely without overheating or hitting a temp limit.

Just get an adequate transformer for the pump, something rated for 350 - 400W on 24 VDC.

You have to size overall membrane capacity and pump flow proportionally. If you increase pump flow only, you won't push any more permeate out (that rate is fixed based on membrane rating at a given operating pressure). But you will reduce recovery rate, which will limit membrane fouling. Recovery rate is defined as a % where permeate out / flow in at each membrane and should be kept as low as possible. These membranes do well around 15 - 25% max.

If you just increase membrane capacity without increasing flow, you are going to INCREASE recovery rate in the membranes towards the end in series. That will make them foul up and not perform as well.

I have a video that explains this on YouTube along with many other videos on how to flush, clean and store the systems.

https://youtube.com/playlist?list=PL...AlGwwLBwh0jcUb

Between runs, no need for peroxide. Just flush with new filter and permeate with needle valve open. Use that new (now rinsed with permeate filter) for your next sap batch.

That 2.6 lpm is the flowrate of the pump at 100 - 110 psi. This is equivalent to approx 40 gallons per hour or 0.67 gpm.

[BartzFarm]

My pump does not have a thermal switch. That’s why I was thinking of attaching one with a 150°F rating. However, after running it for 4 hours at 110 psi and pulling 2.8 amps, the casing temperature only reached 100 degrees.

The spec sheet has a graph that “denotes continuous operation capability at designated pressure and current.” It also states, “At this current or lower, the pump may run continuously, unless the surrounding temperature exceeds 70°F” Wouldn’t it seem logical then, that since I’m running it outside in 40-degree temps, I should be able to run continuously at 110 psi even if I’m pulling 2.8 amps? Or am I missing something?

I didn’t think the 5300 series could run on low input. The 5800 series can do a 7-foot lift but I gravity feed it and warm the sap to around 90 degrees.

I already bought a 24 VDC 10-amp (240W) transformer when I thought I’d be getting the 8900K. Do you really need 350-400W? That seems excessive or will this pump actually exceed 10 amps? Unfortunately, I can’t use it on the 5800 because it’s 24 VAC but I do plan on getting the 8900K eventually.

Great advice on the membranes. I’m going to need some time to wrap my brain around it.

I’ve watched and read many methods of cleaning. I’ve seen most all your videos and some of them more than twice! I love your set up in the cooler, by the way. Most people use lye (RO Soap) but I’m using hydrogen peroxide. At least for the first year. My runs are a week apart and I read that if you’re not using it for more than a few days you should clean it. I just want to know if it’s safe to leave it in the system between runs or do I have to flush it out with permeate after the initial cleaning. I thought if I let it soak for several days to a week it may be beneficial (It's already been a week and I'm hoping there's no damage)

How did you find the 2.6 lpm. Was that on a spec sheet? Or did you calculate this yourself? All I could find was stats such as >4.5 LPM @80psi.

Thanks again for your help!

[carls47807]

Aquatecs will run on 24v dc as an fyi.

[BartzFarm]

Aquatecs will run on 24v dc as an fyi.

Huh, Thanks, I really had no idea. I just spent $30 on a 24 vac 3 amp transformer. I wonder why Aquatec Tech Support never mentioned that?

Haha! Just found out my order was canceled and was issued a refund.