DPD Powder

[Arizoniann]

Hello! I recently bought a DPD powder (R-0870) replacement for FAS-DPD test. I noticed the powder is more of a white color, where the previous powder was more of a gray color. Then after adding two scoops of powder to the water sample (10 ml), the water did turn pink but it also is a little cloudy. Before, the water sample would turn pink but be a "clear" pink, not milky/cloudy. Did I get bad powder? I noticed the container only says DPD Powder not FAS DPD Powder, but the number is still the same (R-0870). I can't tell if I got bad powder, the wrong powder, or if something is wrong with my pool water.

 

[JoyfulNoise]

Welcome to TFP Ann (I read your intro post as well).

The R-0870 powder is supposed to be white. So you have a fresh batch!! The powder changes to a grey color (hopefully very slowly) over time with exposure to air/humidity. However, as long as the powder isn't clumped up into black/purple chunks, it's ok to use.

Where did you get the powder from?

The cloudiness you're seeing is normal with water that has higher CH levels. Have you measured CH recently? I'm in Tucson and my water is about 4 years old. My CH is at 1100ppm. With you being in Gilbert and having a new pool, I bet your CH is a fair bit lower than that. But I noticed the "cloudy" sample water way back when my CH was above 400ppm. It doesn't affect the readings at all. I could go into the chemical reasons for it, but I don't want to bore you into a coma....

 

[Arizoniann]

Thank you so much for your reply~it's a relief to hear that my DPD powder is good. I bought it from Amazon (Amato). It's tough buying test refills here because the mailboxes get so hot! I imagine people who need medications shipped struggle with that too. Do you just make sure you have all your refills before April comes around? I think that's what I need to do. It has been awhile since I tested CH, the last time I did, it was at 550 I believe. I think I read that CH isn't as much of a concern, that it can be higher without causing problems, so I let it go. I will test it again. Thanks again so much for your help!

 

[JoyfulNoise]

Thank you so much for your reply~it's a relief to hear that my DPD powder is good. I bought it from Amazon (Amato). It's tough buying test refills here because the mailboxes get so hot! I imagine people who need medications shipped struggle with that too. Do you just make sure you have all your refills before April comes around? I think that's what I need to do. It has been awhile since I tested CH, the last time I did, it was at 550 I believe. I think I read that CH isn't as much of a concern, that it can be higher without causing problems, so I let it go. I will test it again. Thanks again so much for your help!

Yep, at 550ppm you would definitely start to see some cloudiness to the test. Again, it has no impact on the results.

I too have ordered from Amato and yes heat can be an issue. You should definitely try to get all your testing chemicals early so nothing sits outside in a hot mailbox. Heat can easily ruin them.

As for CH, it does matter but it depends on your pool surface (update your signature with your pool details so we can help you better). If you have a plaster pool then you'll want to use Pool Math to keep track of your CSI. The CSI is your water balance with respect to calcium. For a plaster pool (and especially ones with an SWG), keeping the CSI around zero or slightly negative will keep you from having serious scaling issues. If you let your CSI get too positive, you run the risk of getting calcium scale. PoolMath does all the calculations for you so all you need to do is enter pH, TA, CH, etc, etc and you'll get he CSI value.

As an example of calcium build up, my pool would increase in CH by almost 200ppm every year. In AZ, we have HUGE evaporation rates over the summer months, so much so that on average you are basically evaporating away your entire pool volume every year (unless your pool is covered). So, while you'll never have to worry about your CH falling, you should keep an eye on and test about 2 or 3 times per season just so you know where you're at.

 

[Arizoniann]

I do keep the pool covered, but today I noticed the temp was 98 degrees! Too hot! In the summer I keep the cover off, unless we have a dust storm. I will be sure to go to PoolMath and enter all my tests. I see you use more than the K-2006. That's the one I use. Would it be helpful for me to get the other tests you have? Or will just the K-2006 be okay?

 

[JoyfulNoise]

I do keep the pool covered, but today I noticed the temp was 98 degrees! Too hot! In the summer I keep the cover off, unless we have a dust storm. I will be sure to go to PoolMath and enter all my tests. I see you use more than the K-2006. That's the one I use. Would it be helpful for me to get the other tests you have? Or will just the K-2006 be okay?

I actually have a Plano tackle box full of Taylor reagents, beakers, measuring devices, SpeedStir, etc, etc. So I once, a long, long time ago bought a K-2006 but have since graduated to my "junior chemistry whiz" box...I think I still have the blue Taylor box around here somewhere.

I purchased the K-1001 at the start of last season because I just wanted a quick FC test and pH. But then I also purchase a #9056 high range comparator block as well. I find I can easily determine my FC for daily testing just doing the color matching with the DPD reagents (R-0001 & R-0002). Then, I save my comprehensive testing for the weekends. I have a saltwater pool and an SWG so having a K-1766 salt kit is a MUST HAVE test in my opinion. Finally, I have tests for phosphates (K-1106) and a homemade test for borates (mannitol test).

Eventually testing becomes very routine and, if you do it enough, you can practically just gargle with some pool water, spit it out and know where your chemical levels are at....at that point, pool care becomes so boring that you start to just invent problems with your pool so you'll have something to fix....either that or they make you an TFP Guide and you have to help others....

 

[Arizoniann]

I don't test every day anymore, well in the summer I do, but when I first got my test kit, I tested every day and wrote it all down in a notebook I no longer write stuff down. But should I get a phosphate/borate test? Or is that for salt water pools?

 

[JoyfulNoise]

You only need a phosphate test kit if you plan to treat your pool for phosphates. Most people on TFP don't bother, I'm one of the intrepid few that do. And you only need a salt test kit if you have a salt water pool and SWG.

As for borates, if you do add them, most people find the borate test strips to work well enough. I more of a quantitative person, and a little OCD, so strips are to imprecise for my tastes. You can click on the mannitol test for borates in my signature if you'd like to see the details. Be warned, there's some deep chemistry in that thread.


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[cjpwalker]

... and a little OCD...

Alphabetized it's CDO. Just saying...

 

[mmcwhorter]

I use the TF-100 Test Kit, purchased twice now from the good folks that manger this website. I think it does a great job...does not do salt or borates. I use the LaMott strips for borates and the pool supply store where I get my acid for Salt test.

I see you have said 1100 for CH. And you have a PebbleTec pool. Interesting....I have Marcite....and would never want go above 500 for CH....because the stalagmites/pock marks and pimples I'd find after opening on the pool surfaces (mostly in the spa...and not too comfortable to sit on I assure you...) are everywhere...also white stain marks on the tile above the water line from splashing...so, are you saying High CH at 1100 is OK for "PebbleTec" pool surfaces? Would it not tend to clog a DE type filter faster? Cause build up in a heater faster?

 

[JoyfulNoise]

I use the TF-100 Test Kit, purchased twice now from the good folks that manger this website. I think it does a great job...does not do salt or borates. I use the LaMott strips for borates and the pool supply store where I get my acid for Salt test.

I see you have said 1100 for CH. And you have a PebbleTec pool. Interesting....I have Marcite....and would never want go above 500 for CH....because the stalagmites/pock marks and pimples I'd find after opening on the pool surfaces (mostly in the spa...and not too comfortable to sit on I assure you...) are everywhere...also white stain marks on the tile above the water line from splashing...so, are you saying High CH at 1100 is OK for "PebbleTec" pool surfaces? Would it not tend to clog a DE type filter faster? Cause build up in a heater faster?

The absolute CH value doesn't really matter all that much and it has nothing to do with what type of plaster surface one has. What one needs to focus attention on is the calcite saturation index (CSI). As long as one keep their CSI between -0.3 and +0.3, their water will remain balanced with respect to the formation of calcite precipitates. If you were having trouble with scaling of calcium in your pool, then your water was not balanced; your CSI was too positive. In a desert climate, there is no way to control CH rise as the average pan evaporation rates are too high; for Tucson, it's over 90" annually which basically means an uncovered pool evaporates away most of it's pool water over the entire year. One would have to keep a pool covered all the time which is typically difficult for freeform pools and impossible to do in the summer months as water temperatures would rise to well over 98F from heat retention. So, the way to manage a pool is to keep the pH and TA in check and ensure that the CSI is 0 or less and there will be no scaling.