Red Sea XL Return Issues

[Pescatarian]

I will first off say that I am new to the hobby, so any help is appreciated.
I recently started a Red Sea Reefer XL 200, everything has been going well except I’m having a hard time with the consistency of flow in the return pump and overflow.

I have my pump running at a constant rate, and everything is flowing fine all day long (water level sits consistently about 1-2cm above the silencer). Im using fish food to help in the cycling process.
As soon as I add a pinch or two of fish food, it throws the water levels in the return and sump all out of order. Within a minute, the water in the overflow rises and starts going down the overflow pipe. The water level in the return pump are of the sump drops, and ATO water dumps in. I wait a little bit, but ultimately have to open up the return flow then turn it back to where it was to get it to normalize again.

I can’t imagine that it is that sensitive to get thrown off by a pinch of food, so not sure what is happening. One theory that I have is that the food pellets (small pellets, and tend to float on the surface) are going through the surface skimmer combs and restricting flow around the silencer pipe? Anyone else have a similar issue when setting up their tank?

 

[blaxsun]

The first thing I would suggest is to check where the water levels in the overflow are. You want the water just at the edge of the emergency overflow with an occasional trickle into it. To achieve this you'll need to slightly (as in 1/4") turn the gate valve closed then wait a minute or two and observe the results in the overflow. Repeat until you achieve the desired results.

Second, I'm not sure how much a "pinch" of food is, but I would try to add it away from the overflow and preferably underwater by way of a feeding tube to ensure it doesn't get sucked into the overflow. You may want to remove the silencer on your main overflow and examine for any obstructions before replacing. Also check the comb along the weir.

Third, I would check your filter socks to see if they're clogged or need replacing. I can't see how a bit of fish food would wreak havoc with your setup unless something else is seriously amiss (I've had fish go into my overflow without any adverse effects).