Help- Least harm to my tank

[Eugenia Whittenburg]

Which would be better? Cause the least harm or future trouble to my seahorse salt water aquarium.

Changing higher percent of water or just cleaning as much (most) of the surface algae out and allowing the "whatever bacteria and other things" that have grown in this water to circulate????

- I have a 1 yr old salt water aquarium 105 gal. With pump going up top.

Fish - 3 nemo's, 2 seahorses, 1 fox face, 1 dory, 1 urchin, 1 small, 2 starfish

- Stagnat Sump water (has been turned off for 4 days)
Normally have running
good skimmer- omega 130 vertex
Not sure size of pump

I have only 1 year experience with ant tanks.

I made a mistake. My sump/cycle has been off for 4 days. I did not turn the light off to my refugium/sump and the water got stagnant in my sump causing lots of algae growth in my sump only, water smells, oil substance on top sump water.
If I get all new sump water it will be about 25-30% of total tank/sump water.

Any other advice to help situation from getting worse.

Thanks in advance for your advice
Gina

 

[Dragon52]

If it was me I'd Clean out the sump & replace with clean water. If you have rubble or anything like that clean it also. Use RO/DI water. Pics would help
@Reefsquad

 

[MnFish1]

If the problem is in the sump - yeah - just take the water and algae out...

 

[vetteguy53081]

Lightly siphon the sump without stirring it up as any loose sediment will reach your return pump and enter the tank.
No offense, but seahorse and fish rarely house together successfully as seahorse cannot compete for food. Keep up regular water changes as seahorse are very picky with water quality and do a daily check on pumps, sump and temperature as a routine as equipment does fail, plug up, etc.