Someone please is it mustard aglae

[blackberry]

16x32 inground saltwater pool>Sometimes I think its dirt sometimes algae.This is what i have done bought my FC up to at least 30 and it has held there for 3 days never drop below 20 even after three inches of rain.I have brush and brush will bleach kill it.The pool man says no that it is mustard algae.But im still not sure.

FC30
Total C 30
ph7.6
At 80
ca 35 need to add before turning on the goldline
Hardness i dont add (i dont think i need it)

[chem geek]

Does it grow or accumulate mostly on the shady side of the pool? Mustard/yellow algae prefers shade. As you say, it could be dirt or it could be pollen. If you get a sample and look under a microscope it's easier to tell. Dirt is irregular and solid. Pollen is rounder, sometimes has spikes, but is solid in appearance. Algae is usually oblong and partially translucent.

You could put a skimmer sock in the skimmer and see if you collect pollen which initially floats on the surface before getting waterlogged and sinking.

You didn't list your Cyanuric Acid (CYA) level. The shock level to get rid of mustard/yellow algae is pretty high at an FC that is 60% of the CYA level (normal shock level for green algae is an FC that is 40% of the CYA level). You should make sure you really have algae before going that route or using an algaecide or phosphate remover to kill the algae.

[blackberry]

My CA is 35. It seems to be in the direction of the return water flow.Looks mostly like a dusty of dirt but will collect in spots.We do have a major pollen problem right now even after the three inches rain I live in a 65ac pecan orchard.This is my 1st year dealing with this type of problem.This there anything I can try to see if it is the filter blowing sand and dirt back in the pool.The only thing the pool guy tells me is to let him change out my filter system.The whole thing but its only three years old is it time to change out?

[chem geek]

My CA is 35. It seems to be in the direction of the return water flow.Looks mostly like a dusty of dirt but will collect in spots.We do have a major pollen problem right now even after the three inches rain I live in a 65ac pecan orchard.This is my 1st year dealing with this type of problem.This there anything I can try to see if it is the filter blowing sand and dirt back in the pool.The only thing the pool guy tells me is to let him change out my filter system.The whole thing but its only three years old is it time to change out?

So CA is Cyanuric Acid? Sometimes people use that abbreviation for calcium, though that should be Calcium Hardness (CH).

If it's in the direction of the water flow and you suspect sand or dirt not getting caught into the filter, you can use The Slime Bag in the filtration system to see how much more it catches and if that resolves the problem.

[blackberry]

thanks i will try that

[Pooltech32]

Most filters will have a dial valve on top or the side of the filter, this is used to switch between filter/drain etc. it is possible that the dial valve is not sitting properly and allowing dirt to return to the pool under the returns.
This can be caused by a number of different things, when you move the dial valve does it move smoothly or feel grindy? if grindy then you have dirt trapped under the dial valve and you should take the top off and clean out. It could also be that the rubber gaskets are gone and you need to replace the dial valve. Worst case scenerio is that one of the laterials inside the filter have a small hole in and allowing the sand to return that way to the pool, this would be a bigger job as you would have to remove all the sand and replace the laterials(may as well do them all if this is it) inside the filter and then fill with new sand.

Dumb question, your dial valve is not in the recirculate postion right?

[blackberry]

Ok this is what i have done.The dail does seem to be sticky so i remove and clean it.Hope this helps.Also i put small white socks on two of the water returns could not get the third one a loose.also added to skimmer sock oh what a difference.almost gone this morning except under the return i could not get aloose.Now the stuff in the socks are brown but alittle sticky on the skimmer sock could that be pollen it has been bad.So do you think that means its my filter.Also FC is holding at 20 Also the TC holding at 20 so cc should be zero right?Does that mean no mustard algae I think so what you any of you think.

[chem geek]

Generally speaking, if it's gritty, it's dirt; if it's mushy, it's pollen; if it's slimy, it's algae. I suspect it's pollen. A skimmer sock is a great way to collect it. It does sound like your filter may not be particularly effective as PoolTech was pointing out.