Best chemical/product/brand to descale limescale from hot water tank?

[Imcool]

Hello members,
I am changing "SharkBite U3088FLEX18BVLF Flexible Water Heater Connectors" (waiting for shipment to arrive)

This hot water tank has not been drained /flushed in years so I am wondering if this is a good time to descale the lime deposit from the hot water tank.

I did some google research online and found following information,

1 Citric acid to clean limescale.

2 Vinegar to clean limescale.

3 amazon product based on citric acid to clean limescale.

I will go with citric acid to descale, looks like its a better and cost effective option.

if you know something better to be used for descaling, can you please advise?
This is model for my hot water tank I wish to descale

This is what I found about how much citric acid to use.

Regards

 

[Reach4]

I used phosphoric acid. Mine was Kleen-Strip, sold for concrete etching. I am not saying it was ideal, but a lot of crud came out. I alternated. I also used laundry detergent.

I also used mechanical spraying. I have considered sticking an electric pressure washer wand into the anode hole or the drain hole. I don't know if the tips are narrow enough; they seem to have a wide nozzle on the current offerings. I collected water from my drain hole (having put a 3/4 NPT nipple in there to give a longer bigger passage) into a short plastic tub. I used a small utility pump to pump the water out of the tub, and removed sediment mostly settled into the tub. https://terrylove.com/forums/index.php?threads/draining-tank.62739/#post-465034

I sometimes recirculated the output of the utility tub back into the anode hole, and sometimes out a hose to the outdoors.

 

[Sponsor]

 

[Imcool]

Regards
[/QUOTE]

I used phosphoric acid. Mine was Kleen-Strip, sold for concrete etching. I am not saying it was ideal, but a lot of crud came out. I alternated. I also used laundry detergent.

I also used mechanical spraying. I have considered sticking an electric pressure washer wand into the anode hole or the drain hole. I don't know if the tips are narrow enough; they seem to have a wide nozzle on the current offerings. I collected water from my drain hole (having put a 3/4 NPT nipple in there to give a longer bigger passage) into a short plastic tub. I used a small utility pump to pump the water out of the tub, and removed sediment mostly settled into the tub. https://terrylove.com/forums/index.php?threads/draining-tank.62739/#post-465034

I sometimes recirculated the output of the utility tub back into the anode hole, and sometimes out a hose to the outdoors.

will phosphoric acid not damage any other thing inside tank? what is the exact amount to use, and what strength? with how much water and for how long?
regards