Filter Problem???

[lorettasweet]

OK, I have a 27' above ground pool. Hawyard sand filter. I've just started getting it ready, the pool was left uncovered over the winter. I scouped out the leaves from the bottom, then there was a nice layer of green algae on the bottom.

Also, before I started up the pool, I replaced the sand in my filter hoping it would prevent the problem I had last year.

I started up the filter, added 8 bags of shock, and now the layer of green algae is a layer of sandy-white algae.

I bought a new vacuum and hose today and tried to sweep up the white stuff on the bottom. Within seconds of running the vacuum, my filter starts pushing the white algae back into the pool thru the return. So my vacuuming is pointless since it's just blowing it back into the pool.

Maybe I'm getting more out that I realize, but it doesn't look good.

Last year, I had this problem and found it easier to vacuum the pool with my filter on backwash, thus sending the stuff I vacuum along with alot of water out in the yard. The problem with this, was I would have to stop what I was doing, refill my pool up overnight before I could finish the job.

So I'd love to learn how to vacuum my pool without losing all the water and without blowing the dirt back into the pool.

Should I have tried to vaccum out the algae before I shocked it? Maybe shocking it caused the particals to become smaller and the filter isn't catching them? Just a guess.

Any ideas on what I can do to help?

[Poconos]

Assuming nothing is broken in the filter you can try adding a little DE to basically plug the sand filter a little and catch smaller particles. Quite a few on the forum are doing this. This link has info on the process:

http://www.poolforum.com/pf2/showthread.php?t=3742

Trick is to add slowly at first, maybe 1/2 cup at a time, circulate for 20 minutes or so and watch the pressure. Keep adding 1/2 cup at a time until the pressure increases about 1 psi. Once you know how much it takes to give the desired pressure increase you then add all at once on subsequent refills. Each time you backwash you'll have to replace the DE. Be warned that vacuuming up a bunch of fine stuff can plug the filter fast so keep an eye on the pressure. When it rises about 10 psi or so then backwash. While doing the bulk cleanup you can get away with a quicker BW to conserve water if that is an issue.
Something else to watch for. When you add the DE keep an eye on the returns. The DE should now pass through the filter. If you see the cloud come out then there is probably something wrong with the filter.
Al

[lorettasweet]

OK, my first question is what is DE?

Also, i guess I need to replace this, but my pressure gague broke last year and I never replaced it.

My sand filter calls for 175lbs of sand, my local pool store sold me 150lbs and told me that would be fine. Would being short 25lbs of sand cause a problem?

[Poconos]

Diatomacious Earth. Pulverized diatoms. A fine white powder used in DE filters specifically designed for it. Filters better than sand. Cheap. A 25 pound box will last many seasons and is at pool stores, Home Depot etc for $15 give or take. Also available in smaller quantities. A cup I'm referring to is a 16 oz. cup. Mix in a pail of water before pouring slowly in the skimmer. It will coat the top sand layer. Also...AVOID BREATHING THE DUST. Won't kill you and is inert but can cause silicosis when trapped in the lungs with prolonged inhalation.
Al
Just saw your other question. Being 25# short should not be any big deal. Also, gauges are cheap and you will need one that works. Under $10 at pool stores.

Also found this thread.
http://www.poolforum.com/pf2/showthread.php?t=6744

[lorettasweet]

Great, I will get a new gauge and some DE tomorrow and try again.

Now, just wondering, but when my filter starts shooting the white algae back thru the return while I'm vacuuming, is it still catching the most of it, or am I completely wasting my time when it does this? I'd like to try to get more of it out tonight, but don't want to do so if I'm wasting my time.

[Poconos]

Can't really tell if it's worth the time. Can't easily tell how much is coming out versus what's going in.
Another question...what size pump do you have? Once the gauge is working that will tell a lot.
Al

[matt4x4]

One way to tell if you're catching anything is to backwash and see what kind of crud comes out of the filter.
I find that cleaning up that first load of fine dead algae dust is a legthy process, during the summer, when the pool's used, we tend to get on top of issues right away before they get big, but that spring cleanup tends to be big, you have a lot of inert dirt in your pool too, just hink, 6-8 months uncovered collecting all that dust that lands on it, during the summer, that dust is removed almost immediately because of filtration, during the winter, it just settles in/on the pool.
I let mine run with the barracuda for about 3-5 days straight, the water is milky looking the whole time and things don't look better, but my pressure guage just keeps rising and rising telling me it's building up a good layer of filth in there, I try not to backwash because a dirty filter works better than a clean one (poconos' DE trick is based on the same priciple). I use DE in the summer to "pre clog" my filter, but don't during spring cleanup because there's enough dirt to do the job instead of the DE.

I'm on year 5 now, still the same Zeobrite as year one, have no plans of changing it, I guess I'll have to if I ever lose a lateral, but aside form that, I doubt I'll ever change the media out.

[lorettasweet]

How do I replace the gauge? It looks like it just unscrews out, but I tried to force it and it's not budging. I want to make sure I'm not going to break anything else by trying to unscrew it out. Thanks

[lorettasweet]

Also, the pump is 1.5hp. 27ft round pool.

[Watermom]

Also, the pump is 1.5hp. 27ft round pool.

I think that is probably part of your problem. Like many pools, especially AG pools, your pump is too big for your pool. It is forcing debris through your filter too fast before your filter can catch it and thus, it goes back into your pool through your return.

[Poconos]

The gauge just unscrews. Whoever installed it may have used a pipe dope that hardened. You shouldn't break anything taking it out. When installing the new one get some teflon pipe tape and wrap about 8 turns on the threads then screw it in. If the housing is non-metalic just go hand tight so the housing doesn't crack. Just snug it up at first and see if it leaks. Tighten until it doesn't leak but don't use a wrench.
Al

[lorettasweet]

Thank you all for your help. I got the new gauge in and it's working fine. Was running about 15psi before I added the 1/3 cup of de, that took it to right at 16. It did do a better job of preventing the return from pushing the dead algae back thru, but after a few minutes of sweeping, I'd still have to stop, backwash, rinse, and start over. But it's worked well, I have one more round of vacuuming to do today to get the rest out so hopefully that will be it, then just normal maintenance keeping it clean. I'm excited, temps projected in the 90's this weekend, so I've got it done just in time!

Although, should I be concerned that my pump is too large for the pool? Is that something I should look into changing or will it hurt anything to continue using it?

[Poconos]

With the larger than necessary pump you're just using more electricity than you need however for the cost of a new pump it probably isn't worth it at this time to change. Depends on new pump cost, if you can sell the old one, electric rates, run times. The pressure seems right in range, not too high, so you're not driving the heck out of the filter. Relax, enjoy the 90 deg heat, and send some up my way. I may be in the pool by July at this rate.
Al

[lorettasweet]

I just went out to vacuum again, here's a question regarding the pressure. When I just run the filter, the preasure shows around 17. When I hook up the vacuum, it starts at about 14, then after I sweep a while, it gets up to around 20 before I backwash. I can tell this point because it quits pushing much water out of the return. Should I stop and backwash before it gets to this point, or will it hurt if I continue sweeping at 20 or is there any certain number I need to be aware of to not let it get above?

[Jeffski]

How high does your pressure gauge go (if the needle were maxed)? I wait until my pressure is up about 10psi before I backwash.