When to Replace your Sta-Rite SYSTEM:3® Modular Media Filters - SM Series (Filter Cartridges)

The Sta-Rite SYSTEM:3® Modular Media Filters - SM Series has the industries longest lasting cartridges of any Cartridge Filter. I usually get 8-10 years of use out of them before I replace them for my customers. As long as you clean them at least every six months they should be very long lasting. It is a good thing too that they last so long because the replacement cartridges are very expensive. I buy only the Sta-Rite OEM cartridges when I replace them.

 

So when to replace them? Usually when the pool starts to have issues like the chemicals zeroing out, cloudy pool water and poor flow after cleaning them. They can become very stained also and on rare occasions the pleats can form tears. But since they are so well made it can be tough to know when to replace them and if your pool is circulating fine without issues and the cartridges are old, keep using them until problems with the water quality develop.

You can see from the video that the 450 sq ft ones when compared to a 420 sq ft Cartridge dwarfs it and just by the overall design make it a superior filter over all other brands on the market. If you are looking to install a cartridge filter and you have the room for it at the pool equipment, I suggest going with a Sta-Rite System 3 Media Filter (Cartridge Filter). The problem is that these things are so massive that many pool owners don't have the room to install one.

When replacing the Cartridges I suggest replacing both at the same time. It just makes sense to keep them consistent and replace them as a set. The filter tank and filter parts are extremely long lasting so you will just need to replace the cartridges when they were out as the filter tank itself will last for decades. It is that well made.

Be careful when removing the old cartridges, especially the large one. If it is wet and covered in dirt it can be quite heavy. You can let it dry before removing it or get someone to help you. If your just plain tired of these cartridges you can also try the Retrofit kit for the 300 sq ft and 450 sq ft filters. These are easy to clean but won't last quite as long as the OEM version.

Here are some for sale – note that I do not know this particular online pool store but it seems okay:
http://www.bestbuypoolsupply.com/eden-excel-filters-system-3-retro-kit.html



Here are the four different Medias and links to purchase. The most popular sizes are the 300 sq ft and the 450 sq ft so chances are one of those is installed. Check the label on the filter to confirm your Media size.



S7M120 300 SQ FT:

Sta-Rite 25021-0200S & 25022-0201S System 3 S7M120 Swimming Pool Filter Set - https://www.amazon.com/Sta-Rite-25021-0200S-25022-0201S-System-Swimming/dp/B00768TP7I/ref=as_sl_pc_tf_til?tag=swimmingpooll-20&linkCode=w00&linkId=de3d6b3de216ac61e2195b3f8318cced&creativeASIN=B00768TP7I

S7M400 400 SQ FT:

Sta-Rite S7M400-SET System 3 S7M400 Modular Media 400 - Small and Large Cartridge Replacement Filter Cartridge Kit -
http://www.poolsupplyworld.com/Sta-Rite-S7M400-SET-System-3-S7M400-Modular-Media-400---Small-and-Large-Cartridge-Replacement-Filter-Cartridge-Kit/S7M400-SET.htm



S7M450 450 SQ FT:

Sta-Rite System 3 25022-0203S+25021-0202S Swimming Pool Filters Set S8M150 - https://www.amazon.com/Sta-Rite-25022-0203S-25021-0202S-Swimming-Filters/dp/B00JVS3PQS/ref=as_sl_pc_tf_til?tag=swimmingpooll-20&linkCode=w00&linkId=c2fc42ed66a8d0d28f4d087fb08eb542&creativeASIN=B00JVS3PQS

S7M500 500 SQ FT:

Sta-Rite 25021-0224S + 25022-0225S Full System 3 Pool Replacement Filter S8M500 - https://www.amazon.com/Sta-Rite-25021-0224S-25022-0225S-System-Replacement/dp/B00LPHW848/ref=as_sl_pc_tf_til?tag=swimmingpooll-20&linkCode=w00&linkId=271d3f279e5c70fa1f96e3a2d4644880&creativeASIN=B00LPHW848

Related Videos:

STA-Rite System 3 Filter cleaning: http://youtu.be/d3q19HIm12w

Sta-Rite System 3® Retro-Fit Kit Review and Installation Video: http://youtu.be/ylcO7jTZ9pE

Sta-Rite System 3® Retro-Fit Kit Part 2 of 2: Cleaning the Cartridges: http://youtu.be/waSXKoHZfnw

Installing a Pentair 98209800 High Flow Relief Valve on a Sta-Rite System 3 Filter: https://youtu.be/e3eS2WNawZ8

How to Manually Vacuum a Pool that has a Vacuum Leak (Suction Leak)

In this article I cover how to vacuum a pool that has a vacuum leak, known also as a suction leak. If air is entering the filtration system, this causes the pump to lose prime when you connect a manual vacuum or automatic cleaner to the skimmer. The vacuum leak introduces air into what should be a closed system creating a loss of suction.

Some of the tell tale signs of a vacuum leak are that there is air coming out of the pool return lines constantly while the pool is running, sometimes air will come out of the return lines for the first couple of minutes and then stop. But with a vacuum leak air will come out of the line all the time. When you connect an automatic cleaner or a manual vacuum hose, the pool will lose prime.

One of the problems with a vacuum leak is that the air in the system will cause the pool pump to prime slowly (usually it primes) and a vacuum leak makes it nearly impossible to manually vacuum a pool and will cause your automatic cleaner to work poorly, if at all.

With the air in the system the skimmer will work fine in most cases. It will continue to pull water in at a good velocity and you generally don't have any real issues with a vacuum leak causing the pool not to run, unless the air leak is really large. But when you connect 50 ft of additional hose to manually vacuum your pool, the pump will loss it's prime completely.

Because of the air in the system the pump cannot pull the water the extra 50 ft and the pump will lose prime. Disconnect the manual vacuum hose and the pool primes back up in about 30 seconds. Connect the hose and the pool will lose it's prime again. This can be very frustrating, especially if the pool needs a good vacuuming.

The end all solution would be to fix the vacuum leak. Usually it is the pump lid o-ring, a bad union or a leaking PVC joint. But sometimes it is harder to isolate and the problem will persist for a long period of time. In the meantime to pool is getting dirty. You can of course spend $800 and get a good robotic cleaner that does not require your pool pump and filter, which would solve the problem but is expensive.

Another option is this little trick I have come up with which works in most cases, unless the vacuum leak is just severe. You can use an automatic cleaner skimmer regulator valve to “trick” the vacuum leak. The automatic cleaner skimmer regulator can be adjusted so that while a vacuum hose is connected, some of the suction can still come from the skimmer. So you can vacuum the pool slowly and the pump will hold most of it's prime.

The suction will be pretty weak, but if you move slowly and carefully you can vacuum a pool effectively. I suggest using a heavy vacuum head like the one I use in the video. Here is the link to it and a video on it.

Pentair R201276 Pro Vac #214 Commercial Vac Head – Review: http://youtu.be/JBsXyJUfp3E

Pro Vac Link: https://www.amazon.com/Pentair-R201276-Residential-Commercial-Vacuums/dp/B003840IV6/ref=as_sl_pc_tf_til?tag=swimmingpooll-20&linkCode=w00&linkId=d4e0532cf3227f86c0a494e490adf615&creativeASIN=B003840IV6

If you are a pool service professional this trick will come in handy on your pool route if you cannot isolate or fix the vacuum leak in a timely manner, which happens.

Here are some links for the three parts to connect the vacuum to the skimmer:

Hayward AXV092 Automatic Pool Cleaner Hose Connector: https://www.amazon.com/PoolSupplyTown-Cleaner-Connector-Adapter-Replace/dp/B01FVMNF58/ref=as_sl_pc_tf_til?tag=swimmingpooll-20&linkCode=w00&linkId=02dd24a0c39c02fd0d5f43d5ce92867d&creativeASIN=B01FVMNF58

Pool Cleaner Skimmer Cone Adaptor for Zodiac Baracuda Valve Cuff W70263 W63900: https://www.amazon.com/Cleaner-Skimmer-Adaptor-Baracuda-W70263/dp/B007Q92FEC/ref=as_sl_pc_tf_til?tag=swimmingpooll-20&linkCode=w00&linkId=9df559cf9a2ded952a58a33bbd3d78d7&creativeASIN=B007Q92FEC

Skimmer Universal Cleaner Regulator Valve: https://www.amazon.com/Skimmer-Universal-Cleaner-Regulator-Valve/dp/B00HWDUDK0/ref=as_sl_pc_tf_til?tag=swimmingpooll-20&linkCode=w00&linkId=45d9593ea70385639cce3b46a13a86e9&creativeASIN=B00HWDUDK0

So this won't solve the problem but it will allow you to at least manually vacuum a pool with a vacuum leak, slowly and effectively.

How Long to Run your Pool When you Add Chemicals & How to Set your Timer

In this article I cover how long to run your pool pump when you add chemicals to your pool. Of course the longer you run it the better, but the industry standard is a 3 hour time period with the pump running at standard speed (high speed on a variable speed pump). For optimal results it is best to add chemicals with the pool running.

I also touch on how to set the run time on the pool for a 3 hour period, whether you have a standard mechanical timer or an automated system. Since you will know your swimming pool filter run time it is best to add chemicals when the pool is in it's normal programmed or set time schedule. But that is not always the case and frequently you will need to add chemicals outside of the pool's set run time.

The manufacturers of automated system and of variable speed pumps know this, so they have included a “Time Out” Mode on their automated panels and a 3 hour run time button on their variable speed pumps (Quick Clean) in the case of the Pentair pump shown in this video. So I cover some of the more common automated panels. If you have one outside of the ones in the video you can refer to your owner's manual to see how to put the system in a 3 hour mode.

I have seen some videos on YouTube in which chemicals are added and it is suggested that you brush the area where you added them to “stir them up.” This is really not effective and a waste of energy. Simply adding chemicals when the pool is running or turning on the pool when you add them is the most efficient way to get the chemicals circulating in your pool. Adding chemicals to a pool that is off is less effective and depending on the chemical, say liquid chlorine, the results will be poor.

If you are a pool service professional it is best to get familiar with all of the systems on your route and how to turn them on for the 3 hour mode. On the panels I show you in the video there is a dedicated “Time Out” button. There are exceptions like the Hayward AquaLogic which requires you to press the “Service” button twice to get it to flash and then press the “Pool” button to turn on the pump for 3 hours. The older automation like the Pentair Compool requires you to press the “Pump” button twice – it will flash and go into the 3 hour mode. There are a few more systems out there and some variable speed pumps that I didn't cover for time sake, so you can look that up online or in your owners manual.

It is important to note the “Service” mode button and not to use that on accident. “Service” mode is a 24/7 mode in which the pool's timed run time is effectively turned off. So if you put it in “service” mode with the pump on, it will run 24 hours per day for as many days it takes until you put it back into “Timeout” or “Auto” mode. If the pool pump is off at the time you hit the “Service” mode button it will stay off until you take it out of “Service” mode. So that button should not be used unless there is a problem with the pool and it needs to be left off for a period of time.

I show you the trick I use on the Intermatic timers where I add an extra “OFF” tripper. This is an ideal trick if the pool is running at night only, very early in the morning or later in the evening. This allows you to manually turn on the timer and set it to run for 3 hours without worrying about it running all day and night if you forget to turn it off manually again later.

This will not effect the normal timer run time as the “OFF” tripper prior to the one I add will turn the pool off before it reaches the 2^nd “OFF” tripper. The second “OFF” tripper is only effective if the timer is manually turned on after the timed cycle. So the rest of the week you can leave it on the timer and it won't do anything. If you are going to run your pool heater after the normal set time, make sure you remove that extra “OFF” tripper as it will turn off the heater off if is still on the timer dial. Usually this is not an issue at all and I will leave the extra “OFF” tripper on the dial so that I can add chemicals each week to the pool.

So part of balancing your pool water is adding chemicals, and part of making the chemicals effective is running the pool while you are adding chemicals. I hope this video helps make the process clear and easy for you.

Related Playlist:

Timers & Automated Systems:

http://www.youtube.com/playlist?list=PLsvsTjbpoT-eNtPxDWkf14f2bd-Xrb2hE

Outro video links:

Maintain and Service A Swimming Pool: A Step By Step Guide: https://youtu.be/UmHqL2EvG10

Poolman Tips and Tricks: For Pool Service Professionals and DIY Homeowners: https://youtu.be/sUcjLt9Sk8s

Visit my Website: http://www.swimmingpoollearning.com/

YouTube Video Index – A list of all of my videos:http://poolmandave.blogspot.com/2014/03/swimming-pool-tips-reviews-how-to-video.html

Why the Rio Olympic Pool Turned Green and Lessons We Can Learn From it.

First I want to say that I feel really bad for those who were in charge of the Olympic Pool in Rio that turned green and had to be drained. When I get to a pool on my route and it is looking something like this, I always look around for the customer because it is embarrassing to say the least. If they are not around I breathe a sigh of relief and then I proceed to rapidly turn it around.

So for this to happen in such a huge World Wide venue, I can't imagine the feeling of those in charge. The ridicule and shaming they must now endure has got to be just unbearable. So I will leave it at that and not pile on in this article. But there are many lessons to learn from this incident that we can all apply to our swimming pools and swimming pool routes.

Lesson #1: Stuff like this happens, you need to be equipped with the knowledge to deal with it.

Just today I was at an account and from last week to today it looked like the Rio Diving Pool. It has been in the 100's all week here in Southern California so things can turn ugly very fast. The customer has a Salt System and just as luck would have it, the fuse must have blown a few days ago. So with the heat and no chlorine in the water it turned cloudy green on me very quickly. The customer didn't call nor complain since they have owned their pool for over 10 years now, and this has happened before. They knew I would take care of it and I did.

So things will happen like the motor dying or the filter grids tearing, or you might forget to put chemicals in one week (I am guilty of that one). In Rio it seems someone added Hydrogen Peroxide which in effect destroyed all of the chlorine in the pool. The lesson here is that you need to know how to correct it right away. I have filmed a few videos on how to turn a cloudy or green pool around in 24 hours so you can refer to those if you would like. They appear at the bottom of this article.

The point, know more than basic chemistry if you own a pool. If your pool is blue now, research what to do if it starts to turn green or cloudy. Also research troubleshooting tips for your pool equipment in case of a future failure. Plan for the worst and be ready if it happens. 

The Navy Seals are the most elite fighting force on the planet and when they go into a mission they also have a plan for failure, in some cases a plan for a failure for their plan for failure. So if the most Elite Soldiers plan for failure you as a pool should also.

So whether it is someone dumping in large amounts of Hydrogen Peroxide or a Salt water System failing, be ready for failure. I think there just was no plan in Rio for any kind of failure and they were left scrambling.  

If you don't have the knowledge and your pool starts to go South on you, this leads to panic, a frantic trip to the pool store and $300 worth of chemicals. The pool store employees can see your panic stricken face a mile away. So have a plan in place. If you service pools for a living, the learning curve can be steep for beginners and sometimes there is so much to do each day that if you open the gate and see a swamp on your route you can feel like giving up. So watch these three videos below to gain some practical knowledge before the disaster strikes.

Lesson 2#: When in doubt call a professional.

I don't know the extent of swimming pool service industry in Brazil but I am going to say they have experts in the field like here in the USA. I think maybe they waited too long and tried to correct the problem before calling in the Calvary.  If you have a pool that has turned green and feel you cannot address the problem yourself in a timely manner -quickly, then call a pool service company right away. They will show up usually the same day and start the treatment for you. Time is essential when a pool starts to turn. Even one day can take it from cloudy light green to a swamp.  If you service pools for a living it is okay to sub-contract a green pool out to another company. Better to get it back in shape and lose money than to lose the account. 

The lesson here, if your bleeding out you would call 911 right away. So don't hesitate to call a pool service professional if your pool is turning green. 

Lesson #3: Pools are a real pain.

I am not trying to be sarcastic here, just realistic. Pools are a headache, they raise your utility bills and they are extremely expensive to build. I suppose Rio had no choice but to put some pools in, but if you are considering having one built for your house, housing complex or apartment, think long and hard about it. They require constant maintenance and the return on investment in most cases is very small - maybe a dozen times a season you will actually use the pool. 

Think about it and make a list of pros and cons before you commit yourself to years of work, worry and sometimes frustration. Yes, pools have some real benefits but they also have some real drawbacks. These are some practical lessons for you if you have a pool or are considering a pool.

Rio, I feel for you, I really do. Tokyo, if you need help in 2020 I am willing to go to Japan - I here it is the coolest place on Earth to visit, so call me if needed.

Pentair DORADO™ Suction-Side Pool Cleaner

This is the NEW Pentair DORADO™ Automatic Suction-Side Pool Cleaner. The Dorado is a unique cleaner with bristle brushes all along the bottom to help it clean and scrub your pool surface.

The Dorado is part of Pentair's Trade Grade product line which means it is not sold online but only available from your pool service tech or your local brick and mortar pool store.

The Dorado is based on the Kreepy Krauly Great White cleaner and it has the same internal design of that cleaner. The outer body is the main difference, and I find the Dorado to be an overall better balanced design. The reason manufacturers are making cleaners only available at your local pool store is to basically level the playing field. Retail stores and pool service guys can't compete with the online pricing in most cases - online retailers do not need to keep an inventory, they just simple drop ship an item in most cases.

So to keep pool stores and dealers doors open Pentair offers the Dorado cleaner as well as their Rebel cleaner and certain pool pumps with longer warranties. I like the idea because it is important to support your local businesses and help keep that segment thriving. Nothing inherently wrong with ordering products online,  this just gives consumers more options.

Currently their is a rebate on the Dorado until September 5th 2016:

http://www.pentairpool.com/support/pool-cleaner-rebates.html 

The Dorado is a simple geared type cleaner with actually very few moving parts. This makes the cleaner very reliable as well as very easy to fix yourself.

The bottom sports brushes all the way around and the cleaner has a slight bouncing motion also as it moves along the surface. The opening for debris while odd, is large enough for acorns and other large debris. I like the unique pop out turn mechanism as it is simple yet very effective.

The cleaner also has a bouncing motion as it is moving along the pool floor and walls. This bouncing motion helps loosen up dirt and debris similar to the bouncing motion of a traditional cleaner like the Kreepy Krauly cleaner.

The Dorado has a large cleaning path, 15 inches across. This is great for a large pool as it can cover a lot of area in a shorter period of time. It also is designed to climb the walls to the tile line and the gearing inside will turn the cleaner often to prevent it from getting stuck on the steps or the main drains on the bottom.

It comes with 12 one meter hoses or 40 feet of hose which is plenty for most pools. Also included are the parts to connect it to a pool skimmer or side port/ vacuum port. It is pretty easy to set up, the only thing that is crucial is getting the proper suction. If the suction is too low it just won't work it's way around the pool or climb the walls.

The brush design makes it ideal for pools with a lot of dirt on the walls and the overall design allows it to clean the entire pool in about 6-8 hours. It will spend more time in the deep end and on the deep end walls but if the suction is set properly it will also clean the shallow end of the pool effectively. The manual also makes note of this as most of the dirt and leaves is usually in the deep end bowl of the pool.

It comes with a two year warranty and after that the parts are pretty affordable. Overall it is very easy to work on and the longevity and parts replacements is a plus for this cleaner. You should have minimal problems as it is a very simple gearing program.

I like the Dorado cleaner and it is a solid option for your pool.


Related Videos:
KREEPY KRAULY® GREAT WHITE® Suction Side Cleaner Review:
https://youtu.be/pWHiOulHSNw
Pentair DORADO™ Set Up and Installation Video: https://youtu.be/8YflHTmv3MY
Great White and DORADO Tips and Troubleshooting: https://youtu.be/qptNudQJPhk

KREEPY KRAULY® GREAT WHITE® Suction Side Cleaner Review

This is the Pentair GW9500 Kreepy Krauly Great White inground pool cleaner.  It has taken me some time to get around to reviewing this cleaner but since the release of their new Dorado cleaner, I thought the time was right. This is actually a great alternate cleaner choice if you are in the market for a suction side cleaner.

One thing you will notice right off  is that this cleaner lacks a lot in the looks department. But don't let the plain, flat, and out of date design fool you - this is a great cleaner.  What matters is what is under the hood and the Great White does not disappoint.

It is a simple geared type cleaner with actually very few moving parts. The bottom sports brushes all the way around and the cleaner has a slight bouncing motion also as it moves along the surface. The opening for debris while odd, is large enough for acorns and other large debris. I like the unique pop out turn mechanism as it is simple yet very effective.

The Great White has a large cleaning path, 15 inches across. This is great for a large pool as it can cover a lot of area in a shorter period of time. It also is designed to climb the walls to the tile line and the gearing inside will turn the cleaner often to prevent it from getting stuck on the steps or the main drains on the bottom.

It comes with 12 one meter hoses or 40 feet of hose which is plenty for most pools. Also included are the parts to connect it to a pool skimmer or side port/ vacuum port. It is pretty easy to set up, the only thing that is crucial is getting the proper suction. If the suction is too low it just won't work it's way around the pool or climb the walls.

The brush design makes it ideal for pools with a lot of dirt on the walls and the overall design allows it to clean the entire pool in about 6-8 hours. It will spend more time in the deep end and on the deep end walls but if the suction is set properly it will also clean the shallow end of the pool effectively. The manual also makes note of this as most of the dirt and leaves is usually in the deep end bowl of the pool.

It comes with a one year warranty and after that the parts are pretty affordable. Overall it is very easy to work on and the longevity and parts replacements is a plus for this cleaner. You should have minimal problems as it is a very simple gearing program. I also filmed a video on some common issues and some troubleshooting tips.

Pentair also now sells a Pool Store only version of the Great White called the Dorado. It is the same cleaner but with a new body style and a nicer look and color scheme. It is only available form your pool guy or at a retail pool store.

Related Videos:
Pentair DORADO™ Suction-Side Pool Cleaner Review: Coming Soon!
Pentair DORADO™ Set Up and Installation Video: Coming Soon!
Great White and DORADO Tips and Troubleshooting: Coming Soon!

To order the Great White: https://www.amazon.com/Pentair-GW9500-Kreepy-Inground-Cleaner/dp/B002G9U17U/ref=as_sl_pc_tf_til?tag=swimmingpooll-20&linkCode=w00&linkId=036a7acccb41d53a6d44ccce37c3a89c&creativeASIN=B002G9U17U

Pool Filter PSI: High and Low Filter Pressure - Causes and Cures

In this article I cover the PSI reading on your pool filters pressure gauge. I go over the causes of high filter pressure and low filter pressure. PSI is: Pounds per square inch a standard unit for measuring pressure and the most common factor used in determining when to backwash or clean a pool filter.
A filter pressure gauge is used to measure a filter's PSI and every filter should be equipped with one.

The most obvious reason for high PSI is that the filter is dirty. Simply cleaning the filter or backwashing it if you have a D.E. Or Sand Filter will usually lower the PSI down to acceptable range. The clean starting filter PSI will vary from filter to filter, some hover around 10-15 PSI but many cartridge filters start at 20 PSI. The best way to know in your case is to clean the filter and then mark on the gauge the clean PSI for your particular filter.

A general rule of thumb is that if the PSI goes up by 10, if it is at 15 and goes up to 25, then a cleaning or backwashing is due. This is the best way to lower down high filter pressure and get the pool circulating again.

After cleaning the filter or backwashing it the filter pressure should drop. If it goes back up within a day or  week there could be a few reasons for this. One, the grids or cartridges are worn out and need to be replaced. If you have a Sand Filter the sand could be really dirty and you will need to clean it or replace it. Also, if the pool was recently green or cloudy, the filter could be getting filled up quickly with organic matter. Cleaning the filter again usually will solve the issue. If the D.E. Filter grids have a tear or the top manifold is cracked, the filter pressure can rise rapidly after a cleaning.

If you have a Return Side cleaner connected to your pool like a Polaris 360, the PSI may rise while it is connected due to the back pressure created by closing off a return line and by the cleaners connection itself. This is normal and nothing to be concerned about. The pressure may also be higher by as much as 10 PSI when you switch the valves to spa mode. The back pressure created by the spa jets will cause the filter pressure to rise. A water feature may also cause the filter PSI to rise.

So these are basically the reasons why your pool filter pressure will rise.

If you have low pool filter pressure a number of things may also cause this. The most common reason is some debris is stuck in the pool impeller, restricting it and causing the pump to pull less water. A suction leak like a worn pump lid o-ring will also cause low filter pressure. A problem with the pump's diffuser can also cause this.

Some obvious causes are also a clogged pool pump basket, a clogged skimmer basket and low water in the pool. Too much suction at the side port towards a suction side cleaner can also cause lower pool filter pressure. A clogged inlet line can also be the cause of low filter pressure. If you have a variable speed pump and you are running it at or below 1400 RPM, the filter pressure PSI will also read low.

A broken filter gauge can also create a false PSI reading – either too high or too low, so make sure the gauge is in good working order. They are easy to change and it will only take you a couple of minutes to do it.

I mention that a flow gauge like the FlowVis would be a good investment and if you really want to get the best idea of your pools actual flow, I suggest you install one. That way no matter what the PSI on the gauge, you can see from the flow meter how much water is actually flowing into the pool. This is the best way to monitor your pool's actual flow.

Below are some videos and playlists that cover backwashing and cleaning your pool filter as well as correcting some of the problems the can cause low filter pressure:

Backwash Your D.E. Filter - The Ultimate Guide:  http://youtu.be/j3CleipKc5A
Clogged Impeller, pool pump not priming Part 4: http://youtu.be/tdhkddQKb6M
FlowVis® Flow Meter - H2flow  Review & Overview: http://youtu.be/8WFXje-NWBY

Sand Filter Tips & Troubleshooting playlist: https://www.youtube.com/playlist?list=PLsvsTjbpoT-fsboObxkKbG5qSV-bViuBX

Cartridge Filter Tips & Troubleshooting playlist: https://www.youtube.com/playlist?list=PLsvsTjbpoT-dbjIbwfENL37eYPA-jqPyz

D.E. Filter Tips & Troubleshooting playlist: https://www.youtube.com/playlist?list=PLsvsTjbpoT-fmtXepKd4HK9rp3gznVTUY

Pool Pump Not Working playlist: https://www.youtube.com/playlist?list=PL784D975AEA898B07