Will this pipe layout work

[kadamik]

It was hard to find something online to build the layout I am using. Want to know if this will work? My concern is at the Y connection that both the reactors outputs are connected to. Will the output flow of the UV push back on the output flow of the reactors causing it not to exchange water flow.

Attaching diagram

 

[Sean Clark]

A few things that I noticed:
You want your flow meter on the output as opposed to the input.
You want your reactor ouputs to either be independent or at a minimum be tied in after the check valve on the uv output.
The reactor ouputs will constantly fluctuate as chaeto grows or media clogs up.
This will cause balances over time and require constant valve adjustments.
Another valve between the main return and the manifold will also help keep the pressures balanced. Water will always flow in the path of least resistance.
Ball valves are not designed for flow regulation. They are intended for on and off regulation.
Globe or diaphragm valves are better suited for flow regulation. Gate valves are better than ball valves but again not designed for flow regulation.

 

[cthedaytrader]

A few things to consider, to echo the prior comment, the flow sensor should be after the uv unit, flow is critical for operation of the uv, or it’s useless.

Head Pressure: you really need to calculate and estimate head pressure what what return pump you care using, it’s going to take a monster with a uv, reactors and all those valves and unions, turns, and diameter of the plumbing is a major factor as well. You going to need a pump that deals well with head pressure, most dc pumps can not, I had his issue with mine running varios pumps I lost a ton of flow. You most likely will need sn external or something like an abyzz, depdmin*on tank size and flow goals of course.

Consider two return pumps: I ended up breaking my two return runs into two separate lines with two return pumps allowing me to control the uv separately. Adds redundancy, helps deal with head pressure and control.

I have seen some storied of those back check valves failing so I would still make sure there is enough room in the sump for back flow.

 

[kadamik]

A few things to consider, to echo the prior comment, the flow sensor should be after the uv unit, flow is critical for operation of the uv, or it’s useless.

Head Pressure: you really need to calculate and estimate head pressure what what return pump you care using, it’s going to take a monster with a uv, reactors and all those valves and unions, turns, and diameter of the plumbing is a major factor as well. You going to need a pump that deals well with head pressure, most dc pumps can not, I had his issue with mine running varios pumps I lost a ton of flow. You most likely will need sn external or something like an abyzz, depdmin*on tank size and flow goals of course.

Consider two return pumps: I ended up breaking my two return runs into two separate lines with two return pumps allowing me to control the uv separately. Adds redundancy, helps deal with head pressure and control.

I have seen some storied of those back check valves failing so I would still make sure there is enough room in the sump for back flow.

This is my starter aquarium and I might have over designed it a little. It is only a 90 gallon system. I am using a cor20 and it seems to be keeping up with it so far, and I think the reason is I am using my UV for parasite control at around 100 GPH.

I think on my next tank I will have 2 separate return pumps, I like the idea of redundancy.

I do have a question for better understanding of flow rate of the UV. Would you really see that big of a difference in flow rate if you put the meter before rather than after the UV.

 

[cthedaytrader]

Ahh I assumed it was bigger and still being planned. I overdesigned a 20g system once, and my last system was 75, and it didn’t have UV and i onLu used one return and took the reactors off the return. ( ran and still run carbon in a bag, more gentle on sps systems, rarely run gfo when I do I just use a tlf reactor) my tank now is 150g and added the uv and put the flow sensor after. I think it is more accurate because you are seeing what’s actually coming though, Insm pretty sure I read that or saw it in one of her brs vidoes. I can certainly seeing the uv or a media reactor causing a discrepancy.

this a good brs video on uv, they have a bunch maybe it addresses some issues in there.
You can easily test it though. If you have the flow sensor set up now before the uv, just shut off your valves feeding the reactors though the uv return side, and the just do a timed flow/ volume test and compare it to the flow sensor.