topic for the day: plumbing, pipes, flow, and how to fix: experts welcome!

[Sk8r]

Just fixed a major problem with my tank, and I thought, since this is one of the problems newbies face but not much info comes into this forum---I'd start a thread.

First off: there's two forums that touch on this subject: one is the DIY forum [do-it-yourself], and the other is the Lighting, Equipment, etc. forum. And you will find specific discussions on 'flow' in the sps and other creature-targeted fora. OK? Never fear to ask a question in any of these places.
PUMPS
So...what I know about pumps. "Head" one way pumps are measured: how high can it lift water in its outflow hose. And GPH: that's gallons per hour---how many gallons can it cycle through during an hour. Power---and speed.
There's also...submerged pumps and 'exterior' pumps that cool themselves by pulling cooler water through their works. Both kinds heat your water a little, but submerged pumps heat it more.
If you have a pump that has an 'intake' in your tank where animals can reach it, they will: you MUST guard this, either by getting a rock structure around it [a rock pile] they can't get through, or by putting a sponge or square of filter floss with rubber band on that intake. Creatures like anemones MUST have this precaution. Fish can get sucked in, or trapped against the pull of a powerful pump: this is a nasty fate.
VALVES:
GATE VALVE
It does NOT hurt a pump to put a 'gate' valve in the line: you cut the hose, put the valve in, use 'hose clamps' to secure it on either side, and use the handle to cut down the flow to suit your tank. All the pump 'knows' is that it's harder to 'lift' water: you've just put your tank at a greater mythical elevation than before. It's the 'how high' question applied to reducing the 'speed" element, the GPH. Got it? So if your pump is blowing the daylights out of your sand, try a gate valve.
CHECK VALVE
If you have one area lower than the other, say your autotopoff pump in a reservoir, and you DON"T want the pump to 'siphon' [suck back] all the water it just delivered, plus some, use a 'check valve'. Ask your hardware store: they come in every size from locline to mega-hose. Install it like a gate valve, and it prevents water from flowing downhill.

HOSES AND PIPES: hoses and pipes have an internal diameter and an exterior diameter. This sounds like an obvious thing, except some directions use one and some use another. If you go to the hardware store and buy the wrong one, it won't fit. Go figure. Say you have a hose with a 1/2 INTERIOR diameter. You buy a 'hose barb' [a barbed push-in] connector that fits a 1/2 inch hose. Your mag pump outflow will say it has a 1/2 inch connection: that means it wants an 1/2 INTERIOR diameter hose to go on it. 'Hose clamps' hold a hose in place. Do not use metal where water can reach it.

Hoses and pipes also are designed to bear a certain amount of pressure: PSI means pounds per square inch. The POWERED end of a pump requires stouter hose than the GRAVITY FED hose that just drains down to your sump: mine is super thin---but very tough. I can crush it in my hand, but you can't pierce it with a knife. And cheap. I got this at Lowe's.

There are joints that you can use to 'step down' or 'step up' the internal diameter of a hose. The 'reducing joints' fit inside the hose, and use the interior diameter. The 'expansion' type fits outside the hose diameter, and lets you connect a hose of one diameter to a hose of another diameter. No matter what you find that is the wrong size, you can always rube-goldberg some sort of step-up or step-down that will 'make it fit'. Ask the guys in the plumbing department, show them the two pieces and ask if they've got suggestions.

Teflon tape: you wrap this stuff about a joint, and it makes sure it doesn't leak. The old way involved putty, string, and a lot of mess. Teflon tape makes your inner joint larger, but squishier, and once you jam the other [larger] piece on, it's not going to leak. You can do this with smooth joints or with threaded joints.

BULKHEAD
A two-sided screw-on attachment with a gasket [rubber ring] that makes a watertight connection between an exterior pump and your tank/sump which is filled with water. Screwing this down tight on a tank is a terrifying moment: has to be tight enough to prevent leaks, not too tight [might crack glass]. My advice, do it gently, firmly, and when instinct says stop, this is getting scary, stop, and add water. If it doesn't leak, great. If it does...just one turn more, cautiously. Sometimes a microleak in this situation will solve itself if you just give it time: the seal/gasket will slowly fill the gap.
BULKHEAD CAP: a no-exit little cap that you can screw on to the water side of a bulkhead to shut it off, so you can remove a pump for service.

FLOW
Every time you change diameters of a hose, you affect how fast the water goes from there: narrow it [put on a pointed nozzle] and it speeds up, like a firehose. Widen it [put on a wide, spreading nozzle] and it slows down. That's why a hole in a hose sprays higher than the proper end: tiny hole, big velocity. Reduce or expand a hose diameter via joints, and you're affecting flow rate, speeding it or slowing it down. Remember that 'head' vs 'gph' thing at the start? It's in play here.

Y-JOINT
Literally shaped like a Y. The bottom of the Y has a connection to the hose, and the top has two hoses. Guess what happens to the flow? It slows down. Sometimes each hose has a separate valve, so you can have them in operation independently, shunting all flow to just one side. This is useful in connecting, say, your ro/di unit to the cold line of your washing machine and still having your washing machine able to get water when it needs it. You shut down the ro/di side when it's not in use. THe washing machine has its internal valve that doesn't draw cold water unless it wants it, so you leave that side 'open.'

T-JOINT.
Shaped like it sounds. This REALLY slows water down. If you have too much flow in your tank, you can get it slowed way back by putting a T on the end---or add 2 more hoses and T those off into outlet nozzles: you'll have reduced the flow rate [gph] twice. The same amount of water is going into the tank, but the speed of the water exiting any one nozzle is WAY lower, meaning it no longer knocks your rockwork apart or kicks up your sand.

Anybody who knows anything about plumbing, please add to or correct my info as the mood takes you. Questions are welcome. If I don't know the answer, someone will.

 

[AZDesertRat]

I would revise your post a little. First off a gate valve while it can be installed on either side of a pump should only be used to reduce flows on the discharge side of the pump. NEVER ever reduce the intake or suction side of a pump or you will suffer short pump life, noise, cavitation or all of the above.

I would seriously take out any mention of check valves. Check valves are a BAD IDEA and a disaster or accident waiting to happen . Properly designing your plumbing will eliminate any need for a check valve or other mechanical device that will require maintenance and still fail as soon as you finished servicing it. In my 33+ years in the water wastewater industry I have seen far too many valve failures when one was installed where it had no business being or in the wrong application.

Putting sponges or floss on the suction restricts the flow and again causes problems. Instead use a suction strainer or screen that has several times the surface area of the pump suction so it can partially clog over time and still not restrict the pumps flow.

Teflon tape is one method of sealing threaded joints but there are others that may be just as good or better. My swimming pool contractor turned me on to thread joint sealant sticks years ago and thats all I use on my systems. Its easy to put too much tape on the threads or wrap the tape in the wrong direction and cause problems such as leaks or cracking the fittings. You also need to pay attention to any flashing or excess plastic down in the threads or it will cut the tape, always use a nail or jewelers file and smoothe the threads out first.With the thread sealant which looks like a fat crayon in a cardboard tube, you just push it up from the end and wipe it on the threads then screw it together.

With bulkheads, always put the rubber gasket on the flange or larger side of the bulkhead, regardess if that is on the wet or dry side of the tank. It will not seal if it is on the nut side of the bulkhead. Never overtighten a bulkhead, hand tight plus maye a half turn should do it. Always install bulkheads DRY, no lube, tape of silicone is needed and can actually cause problems by making the gasket want to move or squish out. The threads on the outside of the bulkhead are not pipe threads and are not there to screw anything other than the nut on. Use the internal threads or slip surfaces of the bulkhead for your piping. Never suspend pipes from a bulkhead, always support any piping so it does not cause unequal stress and leaks.

 

[blakesreefbruz]

already a very good thread!! i continually look for help with the plumbing aspect of my tank. Can someone go into the benefits and disadvantages of using PVC or flexible hose in your plumbing and where is best for each type?

Also what are some tips for silent plumbing?

 

[Sk8r]

Ah, bless you, Desert Rat: you're why I advertised for experts...there are 10,000 amateur ways to do plumbing, and there are many fewer expert ways [with a lot better outcome. Let me add about check valves: my only one is in between my kalk reactor and the topoff pump in a 32 g container, so if that one goes, it's not going to do worse than cause me a cleaning job: the amount of water at the topside end does NOT exceed the capaciity of the [bottomside] receiving vessel even under 'full' conditions...which is probably a decent rule.
CHeck valves are NOT good if there's more water up above than what's below can accomodate if that valve sticks 'open', and they are notorious for sticking, particularly if there is organic matter [tank crud] anywhere in the area.

And thanks for that info re bulkheads! I fortunately did mine the right direction, but nobody told me that.

THe reason I used hose instead of pipe when I went to a basement sump [tank upstairs] is that I had to snake 2 ft through the ceiling of one basement room to reach the unfinished side of the basement, and then go along the ductwork of my airconditioning system and then down. I didn't want pipes shaking and rattling as they can do [the hose bucks about a little, on the gravity-fed side] and most of all I wanted no right-angle turns in the arrangement, which can cause clogs if crap gets into it.

Silent plumbing happens when there is no air in the system or irregularity in the flow, as I understand it, and the gravity fed side, the drain, is notorious for both. To put it under positive pressure would require a pump to drain as well as a pump to lift [return] water to the tank, and the chance of one of those going out of time/rate with the other or one outright quitting would be pretty awful. Can you say flood?

As is, your tank is arranged so that it will break-siphon [run out of water available to the drain] if the water sinks too low to reach the U-tube siphon or intake teeth... Your reef-ready tank has a double wall inside the overflow that acts like a baffle, meaning the bottom teeth will stop admitting water when the top teeth run dry.

All of which is to say, that gravity drop is GOING to happen, and there aren't many ways to quiet it. Putting your sump in the basement is one of the best. Two lines drilled through your upstairs floor, and that's all. The tank stand is now available for only lights, food, and scrapers. Much nicer. And your sump is fully accessible. If this is not possible...

You can try to calm the splash below. You can try to adjust the flow into the overflow box so that it doesn't have to fall forever to reach another surface. You would do this by adjusting your pump AND maybe the diameter of your gravity-fed hose, making sure you have enough sump to accommodate the outflow.

ALWAYS be sure your sump can accommodate the total outflow if the pump should power down.

My overflow box is quite deep, and has very little fall, because my gravity-fed hose is smaller than I would like. Someday I may get down under my tank and fix this situation, speeding it up: it is the one place in my system I have a right angle bend, where a spaflex connector fits onto the drain line---I didn't want to do it that way, but I was under a deadline to retrieve my fish from the lfs that was boarding them during a move [they were giving up sale tankspace to help me out] and I had already spent two days looking for a connector: I found a way to 'make it work' so I did it, and my temp fix is still in there. Meanwhile it is about as quiet a downflow as you can get.

Desert Rat or others may come in with some better methods.