SRO-600SSS

There are several common reasons a protein skimmer will overflow but the most common is a chemical within the water itself.

Chemical Reaction - Some chemicals react with the air that the skimmer produces and causes the skimmer to over produce foamate. Chemicals known to cause skimmers to overflow are, red slime remover, medications, reef/frag putties (epoxy Putty) frag glues, water conditioners, dechlorinators, stress coat, NEW filter socks, newly mixed salt, bacteria (seeding) additives as well as other dosing medias. In order to remove these chemicals from the water column we suggest that you do several 20% water changes over the period of a month and add a good amount of fresh activated carbon to the system and change out every week till the skimmer has returned to normal operation.

Water level in sump - It is important that you place your skimmer in the proper water level. It is also important that the output of the skimmer is not submerged under water unless it is properly vented.

Inner water level - If your inner water level is set too high the slightest change in your water chemistry can cause your skimmer to over flow. We suggest that your inner water level to be set at no higher than the collar where the cup meets the body.

Blockage - The air intake otherwise known as the venturi, is like small vacuum pulling air from the surrounding environment. Often collecting dust and debris from the air which can block the proper amount of air to enter the pump increasing the water being pulled by the pump. It is also common for saltcreap to build up in the venturi and will need to be removed manually by scraping it away or dissolving in a solution of vinegar and water. Make sure you inspect the air venture, silencer and air hose for any debris or salt creep deposits. Also be sure the air hose is not bent or too long preventing proper air flow into the pump.

Do you mean the top of the silencer? If you are referring to the two holes on top of the silencer, then just one needs to be plugged. If you plug both, then you will starve the skimmer out of air. If you remove both, then the silencer becomes useless. One cap makes the silencer work. In terms of the height of the water output, it is based on how deep the skimmer is. The skimmer should be placed in 6.5" of water and that will ensure that the outlet is at the correct height.

If you have the skimmer deeper than that, then you will experience overflows. Also, open up the skimmer. If you are trying to force the skimmer to collect by closing the gate valve, then you will also experience radical and intermittent overflows. The skimmer is just reacting to what is in the water. The pump runs at the same intensity all the time without changing so it is not like the pump is running at higher speeds at certain times of the day. If the pump runs at the same speed all the time, then the water is what is changing.

The water level in the skimmer compartment should not change at all. The skimmer and the return pump should be installed in different compartments so the water level does not go down. 1/2" change in water will make a HUGE difference to a skimmer.

What size tank not including the sump? How old is the tank and how old is the skimmer?

When was the last time you gave the pump a good cleaning? Took it all apart and inspected the impeller to make sure it was not cracked or swollen? Soaked all components in a water/vinegar solution?

Oh wow, that is probably the issue and most likely the pump may be damaged. Not performing proper maintenance on the pump is the equivalent to running your car/truck for 3 years without an oil change.