Changing substrate

[JDaugherty3]

Hello again, I would like to change my substrate after I change filter types. I want to remove the UG filter completely. What is the best method of changing the substrate with the livestock I have? 2 clowns, 1 blenny, 7 snails, and 4 hermits. Thanks in advance!

[reeferguru]

What type of substrate do you have now?
do you just have an undergravel filter?
What size tank?
Any liverock?

Is there a way that you can move the substrate to a side and remove the undergravel filter without having to remove the livestock and cloud up your water and tank, by taking out all the substrate?

[JDaugherty3]

I have a 45g FOWLR. crushed coral and sand substrate. 4 big rocks make up the live rock. It will be a challenge to keep the water from clouding up.

[Ninong]

Move your livestock and live rock to a temporary holding container. Almost anything will do, even one of those large plastic tubs that they sell at Home Depot or Lowes with rope handles on the sides. Since you have only four pieces of live rock, you may even be able to include the live rock in the same container with the three fish, 7 snails and 4 hermit crabs. Use water from the tank. You will want to stick an airstone or powerhead in the holding container to keep the water circulating.

Make up a fresh batch of saltwater because you will need extra water when you restart your tank.

Remove your existing sand bed and the UG filter. You may or may not want to save any of the old sand/crushed coral mix. I would probably throw all of it away. You really don't need it to seed your new sand bed. After you have removed all of the old sand/crushed coral substrate, start over with sugar-sized aragonite sand. It doesn't have to be the so-called "live" sand but if you feel like paying extra for it, then go ahead. It won't hurt anything. Don't use any crushed coral this time.

Considering the dimensions of your tank, I would suggest a nice 3" deep sand bed. After adding the sand, try to add some of the new batch of saltwater slowly so as not to stir it up too much. Once the water level is above 1/2" above the sand and the sand has settled down, you can add your live rock. You can then add some of the old tankwater from the temporary holding tank along with some of the new saltwater. I would probably leave the fish, snails and hermits in the holding tank with enough water (say 4" deep) until after the tank is filled and restarted. The reason for that is that the water will cloud up a lot when you restart the tank and you might want to wait a few hours before adding the fish.

Because you have very few fish and only a few pieces of live rock and no corals yet, you shouldn't have any problems making this change.

Good luck!

[JDaugherty3]

Great advice!!

[berkdog]

Just a follow-up question... how often should you change your substrate? Is it recommended? Assuming you vacuum your substrate regularly (every 3 weeks or so) with water changes, but avoid vacuuming too deep.

[Ninong]

Just a follow-up question... how often should you change your substrate? Is it recommended? Assuming you vacuum your substrate regularly (every 3 weeks or so) with water changes, but avoid vacuuming too deep.

If you vacuum your substrate, then I'm afraid I can't answer your question. That's an entirely different approach to the one that I recommend. I recommend never vacuuming the substrate and never disturbing the surface unless absolutely necessary for a particular reason. However, this is a fish-only forum, not a reef-aquarium forum, so I would imagine that many fish-only aquarium hobbyists do employ a different approach to the one that I prefer for a reef aquarium.

For a reef aquarium, I wouldn't ever change the substrate unless absolutely necessary. A healthy, properly-functioning deep sand bed in a reef aquarium should be self-sustaining for quite a few years, certainly more than ten years, if properly maintained. I know of one Japanese hobbyist who kept a 10" DSB going for 20 years before he upgraded to a larger 650-gallon reef aquarium. I know of an American hobbyist who kept a 5" DSB going for 15 years before he dismantled his tank due to a move.

I think that hobbyists who have run into problems with their deep sand beds after only a few years weren't doing things properly. However, that's a subject that has been very thoroughly discussed online and there are several excellent articles by Dr. Ron Shimek, Dr. Rob Tooner, and others, on the proper construction and maintenance of a healthy deep sand bed. I have posted links to articles by both Shimek and Toonen several times previously on this board.

[JDaugherty3]

Well, I took out the undergravel filters, and installed a HOB filter. The water looks very good, havent tested it yet. I will test it tomorrow and post the results. I did not change the substrate though. After everything settled, I vacuumed all the crap off the bottom. It looks alot better! So on this HOB filter, what are the best filter pad things, and how often should I change them?

[Ninong]

I am hesitant to say anything more at this point because I hate to give the impression that I agree with your approach. In my opinion, it was very important to remove your old substrate because of its composition. Now you will be faced with the problem of what to do about it later on down the road.

I don't believe that HOB filters are a good way to run a reef aquarium. A simple protein skimmer would be much better. However, as far as which filter pads for your HOB and how often they should be changed, I suggest you follow the manufacturer's recommendations.

Perhaps you will consider upgrading from your present HOB filter to a protein skimmer sometime in the future. However, removing your old substrate and starting over without any crushed coral in the mix is something you should have done now so that you don't have to deal with this problem in the future.

[JDaugherty3]

Thanks for the info. I'm not looking to have a reef tank!!! I am happy learning my new hobby with a FOWLR setup. I do have a protein skimmer!! All my tests came out good, and I have never been happier with the appearance of my aquarium!