Hello. I am a novist to everything that boys were taught to do when I was growing up, at least in my family. I learned however that the only questions that are stupid are the ones not asked. So, here goes. I have a small koi pond that has a pump moving water continuously. Area is about 12 feet long, 5 feet wide and 3 1/2 to 4 feet deep. It has small waterfall . OK, so... In less than 24 hours time, I start to hear a noise from pond. Upon inspection, I find that the basin that holds the pump and usually filled with water is very low and pump sounds like it is sucking air. I have filled the basin now everyday for about 3 weeks and I can not see or find a visible leak. I have also tried filling the pond itself first and than filling the basin and that seems to extend the time between fill ups so to speak. I had this thought which leads me to this question. I noticed there are about 3-4 screws with bolts on the inside of the upper 2 inches of the basin and one srew and bolt that attaches to that floater thing on opposite side that is worthless. Could water be leaking around these bolts enough to lower the water in the basin? It is winter so if cold weather causes contraction then perhaps the plastic basin is contracting a smidge and hence water seepage? Nothing different has been done since summer and I add water but less frequently and with evaporation, that makes sense. I have had this koi pond for about 10 years and no allegae trouble or anything else. As a matter of fact, I was told with such little space, never to expect babies. I had 5 koi for the longest time and this past season, I have six more and mixed coloring. I think that may mean I have more females than males? Just a guess. QUESTION: Could I use that amazing GOOP to cover those bolts and screws as a seal before filling the basin. Sunny day here, temp in lower 40's, for time to dry. I am afraid the pump will burn up soon as I am not always available to refill as it now needs! Sorry for this long message, as previously stated, I am a novist, green as the spring grass. Thank you. Respectfully submitted, tatntorn

There are sevral versions of Goop, try Plumbers Goop.

I've also had good luck with ShoeGoo.

Does the drawing below represent (in principle) what your pond, pump and basin looks like?

Hello, Sorry for my delayed response, been very busy. My pond has the waterfall at the back end of your drawing. (water fills up over this netting bag of charcoal) then flows out and over the rocks, and down in the pond. Looking directly at your drawing as a (right hander), the pump is actually about 45 degree angle with end basin turned (R) toward me.
I turned the pump off for 72 hours and the water level went from 29 inches to 21 inches? Still could find no obvious water leakage. This pond was built between three outside walls. The exterior of my home is DRYVIT. I had someone check under my house last winter and reported no leak in the area under where this pond is. I have taken pictures of this pond and could send them to you if allowed. In the past, I have pond professionals here but all they have done is replace my pump twice, clean the rocks and say there is no leak. Once they completely drained the pond, but missed a fish that I found dead in the basin ? I also have dimensions of the pump if needed ? Please advise. Thank you in advance. tatntorn (Carol)