Installing a drain valve into inlet pipe?

[THG]

Hi all

I'm new to the forum and wondering if anyone can help me figure out why, either what I've come up with is a bad idea, or why it's not easy to find the parts for.

I have a 1000EF filter with 15mm two tubes that connect, one for the inlet to draw water from the tank and a second outlet that returns the filtered water.

Obviously I know the benefits of hoovering the substrate, but sometimes I don't have time or its not necessary and I just want to perform a quick water change. Rather than syphon the water out, I want to add a T Junction Diverting valve to the inlet pipe, between the filter and where the water enters the tank - the theory is I can turn the valve to divert water from re-entering the tank and just get pumped straight into a bucket/drain whatever...

But for the life of me I can't find a barbed 15mm T junction diverting valve. The only ones I can find are 14mm but I can't also find 15mm to 14mm connectors. I feel like I should have registered for a plumbing forum, not an aquarium one, but there you go. Opinions and advice appreciated. Thank you

[TOtrees]

It can be frustrating, for sure. 

Ideally, what you want is a valve that has the correct barb fittings, that will only allow water to go in one of two directions. Typically, that’s called a 3-way valve. But even then, that you’re in different things. It may be that your best bet is to get a simple tea that interest the size of your tubing, then add valves to each side of the output as necessary. It would mean two hours to turn instead of one, and More fittings, overall, possibly. The other option is to find a valve that works in some other size or format, and adapt from the tubing to the valve format, and back again. 

Unfortunately, it comes down to research and reading. 

Also, whatever solution you end up with will need to reflect what you can actually get, whether that’s from big box, local supply or online.

[THG]

Ah good thinking, those are a little easier to come by. thinking about it more, I could install another on the other side of the pump to draw the new (tapsafe treated) water back into the pump before it heads to is usual outlet inside the tank

[TOtrees]

On 10/3/2023 at 11:02 AM, THG said:

I could install another on the other side of the pump to draw the new (tapsafe treated) water back into the pump before it heads to is usual outlet inside the tank

This would be more complicated, and there's a greater risk of losing the prime on the pump. Since your pump is your filter, that would be problematic. 

I think you might want to consider a sump, instead of a filter, if you want the specific functionality you're describing. Typically, drain (water out) is gravity fed from main tank to sump, and the return pump is always submerged in the sump. So you'd merely divert the gravity fed water coming out of the tank, and then refill the sump. Typically this means that the water level in the sump goes down then back up during a change, but the main tank level doesn't change. Sumps are more typical of saltwater setups, but they can work for freshwater too. 

Edited October 3, 2023 by TOtrees

[THG]

I did wonder if a massive air bubble in the additional inlet pipe would cause issues. I have a separate external pump that I can use to pump water back in so maybe I'll continue to use that- thanks for your help 

[tolstoy21]

Do you have the pump in a sump or is it a canister filter? 

Just re-red your post, I see it's a cannister.

Are the inlet and outlet pipes rigid PVC or flexible hose?

Edited October 3, 2023 by tolstoy21

[Ben P.]

Licensed plumber here! Personally I would just use two valves.  On your outlet add your T like you're thinking, put a ball valve on your tank supply and one on your drain.  Open the drain before closing the tank valve.  You have to have one or both open, cannot have both closed. 

[AndEEss]

I'd do something like this:

https://waterandlens.com/planted-tank-automatic-water-change-overview/

 

Edited October 17, 2023 by AndEEss

[tolstoy21]

On 10/3/2023 at 11:23 PM, Ben P. said:

Licensed plumber here! Personally I would just use two valves.  On your outlet add your T like you're thinking, put a ball valve on your tank supply and one on your drain.  Open the drain before closing the tank valve.  You have to have one or both open, cannot have both closed. 

Would a three way T valve work? Just curious and looking for an expert's opinion.

Setup like this -- 

Edited November 9, 2023 by tolstoy21

[Ben P.]

It would but there's two reasons I would not use it in this case.  First is that if you put it in backwards you could stop flow.  The worst thing you can do to a pump is block it's flow.  Second is price and availability.  I guess a third would be simplicity.  It's pretty hard to screw up two valves 

This is how I have my fry system piped for the same reason.  Just open the valve on the left and it empties tank. 

@tolstoy21

[rgb_aquarium]

I think it the same concept as some of the Fluval canister FX series. They have a drain valve at the bottom of the filter. Cooler suggestion. What if you also add a battery powered blue tooth control valve? One of those you install on faucet for irrigation. Then at a click of a button. Autodrain water change.