Hammer coral not extending as far as it used to

gabedickerson7 · May 3, 2022

Here is a video of my hammer coral. It has been in the tank for about a month and a half now and it seems like it’s not extending out as much as it used to. I just put a new sump and return pump in there with more flow than before so could it be too much flow? Anything suggestions will help I’m still pretty new to this.

vetteguy53081 · May 3, 2022

gabedickerson7 said:
Here is a video of my hammer coral. It has been in the tank for about a month and a half now and it seems like it’s not extending out as much as it used to. I just put a new sump and return pump in there with more flow than before so could it be too much flow? Anything suggestions will help I’m still pretty new to this.

Based on video, hammer looks pretty decent. You could change location as they do best at upper third of tank.
The trick would really be just to avoid the extremes. Avoid extremely bright locations or areas of very high current, and avoid areas that are too dark or with currents that are too low. Fast currents risk damaging the soft, fleshy polyps (and getting an infection). Bright lights will cause bleaching. Insufficient lighting will cause the poor coral to wither away and starve to death.
Hammer corals only require a moderate amount of light for photosynthesis and can grow well in the intermediate regions of your tank. Just about any reef LED lighting should be sufficient for most tanks. Reduce white light intensity and get it off the sand bed which sand can irritate it.
The polyps should sway in the current, but not sustain so much pressure they are constantly bent over their skeleton. Too much flow will tear the polyps (worst case) and cause the polyps do not extend in the first place (best case). So, don’t give them too much flow.

gabedickerson7 · May 3, 2022

vetteguy53081 said:
Based on video, hammer looks pretty decent. You could change location as they do best at upper third of tank.
The trick would really be just to avoid the extremes. Avoid extremely bright locations or areas of very high current, and avoid areas that are too dark or with currents that are too low. Fast currents risk damaging the soft, fleshy polyps (and getting an infection). Bright lights will cause bleaching. Insufficient lighting will cause the poor coral to wither away and starve to death.
Hammer corals only require a moderate amount of light for photosynthesis and can grow well in the intermediate regions of your tank. Just about any reef LED lighting should be sufficient for most tanks. Reduce white light intensity and get it off the sand bed which sand can irritate it.
The polyps should sway in the current, but not sustain so much pressure they are constantly bent over their skeleton. Too much flow will tear the polyps (worst case) and cause the polyps do not extend in the first place (best case). So, don’t give them too much flow.

Ok thanks. Good to know everything is good. While you’re here would you mind helping me out with this brown stuff on my sand bed? I’m not sure what it is. Also seems to be growing on the walls of aquarium but my snails seem to eat it off the walls.

vetteguy53081 · May 3, 2022

I should mention hammer not a good first coral but can be done. Regarding the brown stuff, often associated with new systems is diatoms. Diatoms are a brown algae that typically appear in a reef tank that has just completed its cycle but they can also appear in an established reef tank. They can cover sand, rock, pumps, glass, you name it. Diatoms look ugly but in most cases they are harmless so the key is to not panic when they appear.
Diatoms feed mainly off of silicates but also consume dissolved organic compounds, phosphate and nitrates. Unfiltered tap water can contain silicates and is a good way to jump start a bloom if you use it to mix salt or to replace water that evaporated from the tank. The best way to prevent this from happening is to filter water through a RODI unit, although you can still get a diatom bloom when using RODI if the cartridge that removes silicates expires.
Diatoms are typically harmless to a captive reef and can be beaten once their food source expires. Once you put the kibosh on the source, the outbreak should last a couple of weeks so just be patient and it will pass.

Some reefers dont like or welcome its appearance. For now, you can siphon as needed.
For major outbreaks you may want to consider the three day blackout. Diatoms are easily wiped from the glass with a mag float, a turkey baster or a toothbrush can access other areas of the tank. Be prepared for them to re-establish themselves quickly, they are likely to be able to resettle and have exponential growth rates.
To prevent their return, practice good aquarium husbandry by doing regular water changes, keep the substrate clean, don’t overfeed the fish, ensure your skimmer is running at an optimal level and rinse out filter socks and sponges on a regular basis.
Some cleaner crew to help control it are : Cerith snails, Nerite snails and Trochus snails and also Astraea snails are effective at removing diatoms.