siphon too weak?

Question
Hi, just have a question about vaccuuming gravel. My gravel vac wont suck out some of the faeces. I watch other faeces & dirt get sucked out , but some faeces start to get sucked up, but fall back down to the gravel. I 've just noticed this recently. My tank is std 4 ft 55 gal. & it's been running for 9 years. I keep African Cichlids & the group I have now are just reaching sexual maturity. I feed 1 - 2 times per day(20-30second each time), fast them once a week( not every week though) & 25-35% water change once per week. Doesnt look like worms, same color & size as rest of faeces; just cant vaccuum some out. Is this indicative of any intestinal parasites ? All eat well. Any advice will be appreciated !  Thanks, Tom

Answer
Hi Tom,
The best thing I can think of is either there could be a clog in the hose, the draining hose is too long and/or or the siphon hose is too small. Medium to large size siphons suction water tremendously fast and sometimes you can't really keep up and aren't able to clean all the gravel without draining too much water out. But make sure of no clogs or that simply the hose is too long. Its possible the stuff that looks like faeces may actually be small particles of carbon or gravel too.

I hope this helps!

Happy holidays!
Karen~