Plumbing issues

Dag · #1 12/21/2002, 09:46 PM

In your plumbing article you did not discuss closed loop circulation. Do you have an opinion on that?

Also, can a wavemaker be used on external pumps, or will that damage the pumps?

rexn · #2 12/21/2002, 11:05 PM

Unless I am missunderstanding your use of closed loop system, this refers to using a pump to take water from one area of the tank and return it to another. I actually did mention this type of circulation system in my articles though most of the time I was refering to them as internal circulation systems. And while most of the time I was refering to power heads, I also gave an example for head calculation using an external pump in this configuration.

Having said all this I hartily endorse use of such a closed loop system, if you recall my recommended configuration for all but the smallest systems was a combination of internal and external circulation systems. The closed loop system has the advantage of little or no head to work into so it can potentially be a smaller pump for a given flow rate requirement which is desirable from cost, noise and heat perspectives.

As to using wave makers on external pumps - I've done it for many years but you need to make sure of two things before you do this yourself. One, can a given wavemaker handle the desired pump - pumps have certain power requirements in terms of amperage requirements and wavemakers use electrical switches of some sort (normally relays, either mechanical or solid state) and these switches have limitations to the amount of current and voltage they can reliably handle. If you exceed this switches rating by tying to operate too large a pump you will likely cause the wavemaker to fail. The second question you have to ask is will the pump in question reliably turn off and on repeatily, for some pumps the process of turing off and on is more stressful and in these cases use with a wavemaker is not recommended. Unfortunatly the only way I know of telling whether a pump can reliably run on a properly size wavemaker is to try it or know someone else who already has (the maufacture may be able to tell you as well but as most larger external pumps used in aquariums are not specifically designed for this use they may not know).

In my own personal experience I have been able to successfully use Iwaki 30s and 40s on wavemakers for years as well as MAK4s, on the other hand I blew up several larger Rios (2500's) in similar fashion and have had more than one person tell me that Ehime hobby pumps also have difficulties on wavemakers. Again, the best advice I can give is to ask around and see if someone else has done your homework for you and already demonstrated success with a given model of pump on a wavemaker.

Hope this helps, RN

rexn · #3 12/21/2002, 11:10 PM

Unless I am missunderstanding your use of closed loop system, this refers to using a pump to take water from one area of the tank and return it to another. I actually did mention this type of circulation system in my articles though most of the time I was refering to them as internal circulation systems. And while most of the time I was refering to power heads, I also gave an example for head calculation using an external pump in this configuration.

Having said all this I hartily endorse use of such a closed loop system, if you recall my recommended configuration for all but the smallest systems was a combination of internal and external circulation systems. The closed loop system has the advantage of little or no head to work into so it can potentially be a smaller pump for a given flow rate requirement which is desirable from cost, noise and heat perspectives.

As to using wave makers on external pumps - I've done it for many years but you need to make sure of two things before you do this yourself. One, can a given wavemaker handle the desired pump - pumps have certain power requirements in terms of amperage requirements and wavemakers use electrical switches of some sort (normally relays, either mechanical or solid state) and these switches have limitations to the amount of current and voltage they can reliably handle. If you exceed this switches rating by tying to operate too large a pump you will likely cause the wavemaker to fail. The second question you have to ask is will the pump in question reliably turn off and on repeatily, for some pumps the process of turing off and on is more stressful and in these cases use with a wavemaker is not recommended. Unfortunatly the only way I know of telling whether a pump can reliably run on a properly size wavemaker is to try it or know someone else who already has (the maufacture may be able to tell you as well but as most larger external pumps used in aquariums are not specifically designed for this use they may not know).

In my own personal experience I have been able to successfully use Iwaki 30s and 40s on wavemakers for years as well as MAK4s, on the other hand I blew up several larger Rios (2500's) in similar fashion and have had more than one person tell me that Ehime hobby pumps also have difficulties on wavemakers. Again, the best advice I can give is to ask around and see if someone else has done your homework for you and already demonstrated success with a given model of pump on a wavemaker.

Hope this helps, RN

Dag · #4 12/22/2002, 02:47 AM

Thanks. By closed loop, I was referring to pulling water from the tank and returning it with an external pump without any air contact (including not running it through the sump). The discussion in your article of external pumps was primarily, if not exclusively, in connection with the use of a sump.

I was contemplating the use of two Iwaki RLT100 or Iwaki RLT70 with a Wavemaster Pro. Perhaps you have experience with that, or know someone who does?

rexn · #5 12/22/2002, 11:30 AM

Unfortunately neither the Iwaki 70 or 100 will work with the Wavemaster Pro as it is only rated at 120 watts per pump (360 watts total for three pumps) and the 70 runs over 300 watts and the 100 is about 400 watts.

If all you are planning to do is to operate these in a close loop system then these pumps are probably not all that appropriate anyway as they are fairly high pressure rated pumps (30-40' max heads) which is uneccessary in a close loop circulation system that operates into very little head.

Have you considered the Dolphin AmpMaster series? These pumps are primarily designed to give high flow rate (as high or higher than the Iwakis) but with little or no head capability (max heads run barely over 10'). They require much less current (typically 1 amp or less) and most would fit within the Wavemasters operating limits (though near its max). I never have used one of these with a wavemaker so you will likely have to ask around to find out if they are compatible operating in this mode (in this case the manufacture may very well be able to give you guidance on this). The other aspect of using this pump or one like it is that you normally have to run larger diameter plumbing (or parallel lines) to minimize head loss due to the pumps poor pressure capabilities.

Again, I am assuming that you are purely running these pumps in a pure closed loop circulation system, if any inline filters or if the plumbing runs are excessive (>10-15') then the low pressure pumps are less appropriate depending on what your flow rate goals are. If you do need more pressure capability then you need to find a wavemaker system more capable than the wavemaster that will handle more powerful pumps such as the Iwakis.

RN

Dag · #6 12/22/2002, 12:13 PM

Thanks. I'm debating between two systems, which could be used in the alternative or complementary. Neither of the contemplated choices involve powerheads or the like.

I am using a remote sump in the basement. How do I return the water from the sump to the tank? I could use one pump or two in the basement. If I use two very strong pumps (such as Iwaki RLT100) I could put the two pumps on a wavemaker. This would presumably create lots of chaotic flow. This might be all that is necessary. Some would say, however, that running so much water through the sump (4000 GPH or so) would create bubbles. Hence, the consideration of the closed loop circulation with an external pump. Other advantages of using the closed loop may be less electricity (why move so much water up and down to the basement?) and the ability to create flow at different levels of the tank.

If I use a closed loop, that might render the wavemaker unnecessary because I might have enough flow (albeit not random) without it. Under this line of thinking, I would use one strong pump in the basement to return water from the sump, and another pump under the tank for the closed loop circulation (or if I wanted even more flow I could create two closed loops). Under this approach, I don't have to worry about compatibility issues between the wavemaker and the pumps. (Of course, there's always overkill: two pumps in the basement on a wavemaker) and two closed loops.)

I'm obviously very confused. Any light that you can shed on this would be appreciated.

Dag · #7 12/24/2002, 11:31 AM

I hope you are having a safe, healthy and happy holiday and that at your convenience, you'll have time to respond.

This is in reference to a 200 gallon reef tank with a remote sump in the basement and using an additional closed loop.

Rather than using a wavemaker on the pumps, the better course seems to be to use actuated (or motorized) ball valves.

My current thinking is to locate both pumps in the basement. One circulation loop will pull water through the sump using an Iwaki RLT 100. The other circulation loop will be a closed loop powered by an Iwaki RLT 70 or 55. Both loops will have actuated (or motorized ball valves).

rexn · #8 12/24/2002, 11:11 PM

The mortorized ball valves are certainly a viable option for controlling larger pumps, just make sure that the valve size matches the dischage diameter requirements of the desired pumps.

The Iwaki 100 seems resonable choice for your sump pump though to be honest I would normally recommend a couple of smaller pumps (55's?) rather than a single large pump to help improve reliability in case you have a pump failure. This could be especially true if you are controlling your tank temp from the sump (heating and/or chilling). Multiple sump pumps also give you more flexibility in terms of randomizing your flow patterns.

As for your close loop pump, the Iwaki 55 or 70 will certainly work but again you are paying more for power and heat than you need due to to these pumps higher pressure capabilities. Even running from the basement, a close loop pump requires lower head capabiolities as the effective head (that measure from the water level at the pump input to the water level at the pump exit) is typically near zero so only the plumbing losses themselves have to be over come by the pump which can be minimized by using larger diameter plumbing and minimal number of elbows.

My last recommendation may be redundant but just in case, place valves (non-motorized) on both external pumps inlet and outlet near the pumps themselves inconjuction with unions to help facilitate removal and/or maintainance.

Happy holidays, RN

Dag · #9 12/25/2002, 01:23 AM

My only concern with using more pumps and loops is that I think that means more returns in the tank. I wasn't planning on running the sump returns through the internal overflow box, so I'm concerned about having a forest of pipes ...

Dag · #10 12/25/2002, 01:32 AM

As for the closed loop, so then maybe it makes more sense to go with the RXLT series that is not pressure rated, either the Iwaki RLXT 30 or the RXLT 40?

Dag · #11 12/25/2002, 01:39 AM

Sorry for the seriatim replies, but I'm still collecting my thoughts.

Many people seem to recommend the multiple sump pumps for back up purposes. But I don't really understand this philosophy. It's just pay now or pay later. A small pump nearly costs as much as a large pump. So why pay for two sump pumps now? If the pump breaks, I can order another one shipped overnight, or if I'm really concerned about being without a pump for 24 hrs, I could buy a spare pump. Under the two-pump proposal, you are just using your spare now as opposed to having it lie around.

As for the random flow, the ball valve with one pump provides the same chaotic flow as two pumps on a wavemaker. If I used two sump pumps, and each of them in conjunction with a ball valve, that would be four sump returns. That seems like alot, no?

rexn · #12 12/27/2002, 11:34 AM

The actual size of your various pumps depends on several factors but probably the most significant is what level of circulation you want in your tank.

You obviously want good quality circulation (i.e., reaching all parts on tank in randomized flow patterns) but the magnitude of circulation will dependend alot on what type of critters you plan on keeping. If fish only, then more moderate flow levels are sufficient in most cases but if as I assume you plan on having corals then more substantial circulation levels are typically appropriate and if SPS corals are planned then you likely want even more figorous circulation.

Once you have determined the level of circulation you need then you have to determine how it will be distributed between internal (includes closed loop) and external systems. My normal recommendation is to use just as large a external system as needed to provide enough circulation to provide for temperature control from the sump (just a few hundered gallons/hr is normally sufficient) but depending on your systems requirements you may decide on a higher rate of return. The bulk of the circulation requirements can normally be handled by internal or closed loop systems more efficiently than the external due to lower head requirements. Use the procedures I outlined in my articles along with your specific installation requirements to determine if a given pump is properly sized but for your closed loop system you do not normally need pressure rate pumps.

As for redundant sump pumps for reliability - if you plan to always have someone home who can be there to detect a failed pump and be able to repair/replace it within 24 hrs (assumes closed loop pump(s) are still running) them maybe you do not need redundancy but I know few folks in this situation (most take vacations for a week or two and even if they have someone checking their tanks they may not be sufficiently knowledable to handle emergencies of this type). Also if you have a spare pump to replace a failed pump why not just have two pumps in system as it costs little more. Your concern with multipule returns to tank with redundant sump pumps I would normally consider an advantage but if your installation requirements limits the number of returns you can accommodate then you can combine the two pumps outputs into one larger return (you need to use check valves on both pumps before combining them to keep a failed pump from shunting water back into the sump).

RN

adrinal · #13 02/21/2004, 03:09 AM

Looking for the artical they are refering to

rexn · #14 02/26/2004, 01:31 AM

Check out the April - Jun 2002 issues of Reefkeeping online magazine for a three part series I did on Aquarium pumps.

RN