I bought my above ground swimming pool package in 1990. My Hayward sand filter is a top mount and has a lateral assembly w/center pipe in side of it. The pipe is broken at the top and I need to purchase a new one. The sand filter sticker came off, so I don't know what model the sand filter is, but the lateral assembly has a part number S200F, which I can't find. The lateral assembly from the bottom of the base to the top of the center pipe is 18" in height. Can you tell me which lateral assembly to buy?

Parts can be replaced sure, but will it be worth it compared to buying a replacement or even upgrading. Laterals (if broken sand gets in pool) can be replaced on this unit from 48 off amazon and is cheaper than buying a new unit, same with leaking rings or seals. but if a part of the tank is cracked or something like that you might up spending almost as much to replace a piece of the unit as it would be buy a whole new unit. Amazon has this model for 180$ if repairs would cost more than 80 I would say replace it, these things dont last forever, especially if you live in a cold place that freezes in the winter and it sits in the sun all summer.

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There was also a couple smaller parts on amazon but you should check it out and also compare them to some other places.

Either broken lateral drain assembly or the manifold.

If fairly new filter, it could be that you have overfilled the amount of sand, as it is too close to the bottom of the variable position Multiport filter valve.
Hayward SX244DA Lateral Assembly With Pipe

A little sand in backwash is not uncommon. Many packaged sand filter systems use pumps whose flow rates greatly exceed the flow capacity of the filter.(the more horsepower the better, right? - Wrong) If this occurs only during back flush the the pump is too strong or the sand level is above the beginning of the rounded top of tank. The sand level will eventually correct itself.

The greatest odds are that you have a broken lateral or a few broken laterals. Another less likely cause for getting sand in your pool on filter setting is a cracked/broken stand pipe. This is the vertical pipe running through the center of your filter. Open, clean, rinse, inspect, repair/replace, fill halfway with water, add correct sand weight, and close back up. Always start back up with the key assembly(star valve) in the backwash position so that you don't pump any residual sand back in the pool. After running 15-25 seconds, turn off pump and set to filter position.

The model #711 is a 1.5" valve, not the filter. The following link is for the top mount filters in the pro series http://www.hayward-pool.com/prd/Above-Ground-Pool-Sand-Filters-Pro-Series-Top-Mount-Systems_10201_10551_15009_-1_24001_14018_A.htm

There is only one thing that can cause sand to come back into the pool from a sand filter. The internal assembly, called the lateral assembly, is either cracked or broken. This is an easy fix and should cost you around $70 to replace the whole thing. You need to unscrew the bottom drain cap on the filter to remove the water in the tank. Then, remove the multiport valve on top of the filter. Take a shop vac and remove the sand in the filter. If the sand hasn't been replaced in the last 3-5 years, this would be a great time to do that since you already have the sand out anyway. Then, remove the lateral assembly and inspect the entire thing. After you replace the lateral assembly, you'll need to fill the sand filter tank 1/2 full of water before adding fresh sand. This is done to cushion the laterals from the weight of the sand. Cover the hole in the top of the lateral assembly pipe with a cup or duct tape to prevent any sand from getting inside the pipe (the sand will come out into the pool if it gets into the pipe). Fill the tank 3/4 full of pool filter sand. Make sure it is genuine silica pool filter sand from a pool company. A lot of big box and home improvement stores sell play sand as filter sand. This will cause you more problems!

Hello, 1 You need to unscrew the drain plug and screen (if it is still there!) at the base of the filter. 2 You can reclaim most of the sand by letting the filter drain through a sieve (lots of work) or use new sand. 3 Uncouple union joints or couplers that attach to filter head. 4 Remove filter head. 5 You can try pulling some sand out of the top. However, do not damage the filter fingers in the sand. 6 Use a hose to blast the sand out the bottom drain. 7 Inspect all fingers, replace if necessary. 8 After all is cleaned out, place finger mount inside filter. Cover top of mount with a cup or similar to keep the new sand out of the finger assembly. 9 Replace drain plug and screen. 10 Fill filter halfway with water. 11 Slowly pour sand in and spread evenly. 12 Remove mount cover. 13 Reinstall head, unions and couplings. 14 Prime pump and test for leaks.
Good Luck

Fill the empty and cleaned tank about half way with water, cover the stand pipe in the filter with a plastic cup or some other means to ensure sand will not go down the pipe. Be sure the pipe is centered in the hole. Add 200# of #20 silica sand and once filled use your hand to reach in a level off the top as best you can. The sand will be about half way up the filter and now the water will be near or over the top. Once done, secure the valve in place and connect the hoses and you are ready to go.

Replace the lateral assembly. Be sure to fill the tank just under half way with water before adding the sand back in. Otherwise you risk cracking the laterals.

if u used play sand, or any other type of sand thats NOT pool filter sand, that could be the problem. also if there is too much sand or too little sand that could also cause this.