Katalox backwash very slow

[KCunningham]

I have a 9 inch katalox with a Genesis head. Just upgraded to a 10gpm submersible pump from my 5gpm jetpump.
I did a manual backwash on the katalox and noticed it's pulling VERY slowly, it used to make a big WOOSH sound and was clearly flowing fast (I haven't done a manual cycle in a long time, I dont think the new pump caused this, but now I'm aware of it).
I took the drain apart and there's no obvious occlusion. I also took the flow limiter out of the drain and tried that with no change in backwash flow.
Any idea what's happening here? Bad head? Or?

 

[Reach4]

Monitor the water pressure during backwash. If that stays normal, is there maybe a cartridge filter between the pressure gauge and the backwashing filter?

Could it be that even the old whoosh backwash was inadequate and the media cemented together? But if you had not been doing backwashes, it would not have made a difference if the backwash flow would have been adequate. If you get things fixed, and your tank is not painted (is natural tan) shine a backlight thru the tank, and look for bed expansion during backwash. A 9 inch tank with KL needs about 6.5 GPM of backwash. A 5 gpm pump may be able to do that.

If you do plumbing in the area, and there is anything significant in the path, I would add a boiler drain valve right before the filter. That would let you mount a garden hose thread pressure gauge. If there is no cartridge filter in the path, just watching the pressure gauge at the pressure tank. If the pressure stays above 30 psi, the problem is probably not that the pump cannot keep up.

Was a "long time" 2 weeks, or 2 months?

 

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[KCunningham]

OK when running a backwash cycle the PSI drops from 70 to 55 and holds steady. The only thing between the pump and the katalox is a softener..I've tried running while that's in bypass or service without change (it's also less than a year old). I changed the katalox media last summer after 7 years and it wasn't 'bricked up' so I'm thinking less than a year with the same pump and fresh media also would not be bricked although it's a black tank so I can't say for sure. A long time would be months since I've run a manual backwash cycle.

 

[Reach4]

So what explains the flow drop to you? Cartridge filter or wye filter in the path after the pressure gauge? Pinched pipe? Your drain line could have a pinch/clog in it, and that would slow backwash.

I suggest that you measure the water pressure somewhere after the filter during backwash. You can put a GHT pressure gauge on the WH drain, or a laundry tap. That is a pretty good measure of what the pressure is at the input to the valve, since the valve would normally be in bypass during backwash.

 

[KCunningham]

Good question and I'm not sure.. I do have a cartridge filter, but that comes after the Katalox so I think it wouldn't affect backwashing? I just took off the drain line and there's no clog or kink. No pinched pipe, it's a pretty simple route from the pump to the katalox.
I was told that this system creates a 15psi drop when in service, maybe it's the same for backwash?

 

[Bannerman]

The only thing between the pump and the katalox is a softener..

Why is the KL filter located AFTER the softener? The KL unit should be before the softener.

Just upgraded to a 10gpm submersible pump from my 5gpm jetpump.

What depth is the pump located at, mand what is the static water level in the well?

What is the model of submersible pump?

 

[Reach4]

Oooh I missed that softener statement. Not sure how. Yes, backwashing iron filter should have no more than a wye or other course, low-drop filter before it.

 

[KCunningham]

Why is the KL filter located AFTER the softener? The KL unit should be before the softener.



What depth is the pump located at, mand what is the static water level in the well?

What is the model of submersible pump?

The KL is after the softener because I dont know what I'm doing (which is why I'm here). OK good to know, I can move those on Friday and see if that helps.
The pump is a 1/2hp AY mcdonald stainless submersible pump, that's about all I know. Not sure how deep it is or the static water level but the electrical wire was only 10' long so it can't be deeper than that.

 

[LLigetfa]

Does the KL filter have a top basket? If so, maybe it is clogged. If it doesn't, maybe media got driven up into the head.

If the pressure holds at 55 during the backwash, it is unlikely to be a supply or flow issue at the pump.

 

[KCunningham]

Does the KL filter have a top basket? If so, maybe it is clogged. If it doesn't, maybe media got driven up into the head.

If the pressure holds at 55 during the backwash, it is unlikely to be a supply or flow issue at the pump.

It does have a basket. Friday I'll plan to take the head off and see if there's anything I can see that may be problematic.
Will report back, appreciate the help from everyone

 

[LLigetfa]

My iron filter has a top basket which will clog with iron. As a general rule, it is advised to remove the top basket but in my case, I have an HP tank to oxidize the iron and the air sometimes moves forward with great enough force to lift the media too high so the top basket catches it. I have to frequently pull the head off to clean the top basket.

When I would pull the head, the riser tube would come up with it and would need to be reseated so I had to install a hold-down device on it.

I installed a Tee with a 1" ball valve where I can test the GPM to determine if it might be the top basket that is causing the restriction or if the restriction is upstream. I can also install a temporary test pressure gauge there. I can also use it to introduce air into the backwash stream to generate a more violent stream to break up the media if it clumps or use air in normal (service) mode to displace all the water from the media tank.

 

[KCunningham]

Yeah I'm a bit worried about the riser tube coming up when I take it off. Is there any way to reseat that other than to empty the tank and put fresh gravel down?

 

[LLigetfa]

Is there any way to reseat that other than to empty the tank and put fresh gravel down?

If the tank is where you can overflow the water, you can connect a hose to the top of the riser tube and wash it back down. Alternately if you can drain the tank and lay it on its side, you can roll the tank back and forth while pushing the tube back in.

BTW, the hold-down from Clack is part #D1301

https://www.clackcorp.com/downloads/distribution_systems/riser_pipe_hold_down_clamp_3077.pdf

 

[LLigetfa]

Oh, I should have mentioned... If you drive out all of the water with compressed air, the media and riser tube will be much heavier and less likely to pull up when you remove the head. The tank will also be easier to carry outside if you need to to work the tube back in.

 

[KCunningham]

Well, mixed bag this weekend. Had a noreaster so lost power for a couple days but I managed to take apart the katalox head and check the basket. While the tube didn't come out, I did end up losing the basket to the tank and was unable to fish it out. Couldn't find any clogs. I did redo the plumbing so that the katalox is now before the softener. I also dont think the katalox is bricked as I was able to push a rod into it without much trouble. The manufacturer recommended changing the seals and pistons inside the head..not sure if I'll do that or move on to something different like pro-ox.
The good news is at least for now the quality of the water has improved and no longer tastes like metal.

 

[Reach4]

The manufacturer recommended changing the seals and pistons inside the head..not sure if I'll do that or move on to something different like pro-ox.

In a 9-inch tank, you usually want about 6 or 7 gpm for backwash. With a solid solid manganese dioxide filter media, such as Pro-ox, you need much more GPM for backwash.