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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 O9uifha52EWYmSQ4ym58C54LjEbtqAgmjMGPHAwIrcQVffLIegzmupaeh5faPBzo
 Z4/U6zqyLz7MWLuMxUPRvA==

<SEC-DOCUMENT>0001002105-04-000042.txt : 20040226
<SEC-HEADER>0001002105-04-000042.hdr.sgml : 20040226
<ACCEPTANCE-DATETIME>20040226161834
ACCESSION NUMBER:		0001002105-04-000042
CONFORMED SUBMISSION TYPE:	3/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040217
FILED AS OF DATE:		20040226

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IONICS INC
		CENTRAL INDEX KEY:			0000052466
		STANDARD INDUSTRIAL CLASSIFICATION:	SPECIAL INDUSTRY MACHINERY, NEC [3559]
		IRS NUMBER:				042068530
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		65 GROVE ST
		CITY:			WATERTOWN
		STATE:			MA
		ZIP:			02172
		BUSINESS PHONE:		6179262500

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DICKERSON LYMAN B
		CENTRAL INDEX KEY:			0001280319

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07211
		FILM NUMBER:		04630992

	BUSINESS ADDRESS:	
		STREET 1:		ECOLOCHEM INC
		STREET 2:		4545 PATENT RD
		CITY:			NORFOLK
		STATE:			VA
		ZIP:			23502
		BUSINESS PHONE:		7578559000
</SEC-HEADER>
<DOCUMENT>
<TYPE>3/A
<SEQUENCE>1
<FILENAME>f3a-lyman_ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2004-02-17</periodOfReport>

    <dateOfOriginalSubmission>2004-02-23</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000052466</issuerCik>
        <issuerName>IONICS INC</issuerName>
        <issuerTradingSymbol>ION</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001280319</rptOwnerCik>
            <rptOwnerName>DICKERSON LYMAN B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ECOLOCHEM INC</rptOwnerStreet1>
            <rptOwnerStreet2>2855 NW 75TH AVENUE</rptOwnerStreet2>
            <rptOwnerCity>MIAMI</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33122</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1946926</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Lyman B. Dickerson Revocable Trust, Dated September 9, 1996</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>260622</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Lyman Dickerson Irrevocable Trust, Dated July 1, 1991</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The Reporting Person serves as the sole trustee for the Lyman B. Dickerson Revocable Trust, dated  September 9, 1996, and has the sole power to direct the voting and disposition of its shares.</footnote>
        <footnote id="F2">The Reporting Person also serves as a trustee for the Lyman Dickerson Irrevocable Trust, dated July 1, 1991, that owns 260,622 shares.  Charles C. Kline serves as the independent trustee for the Lyman Dickerson Irrevocable Trust, and has the sole power to direct the voting of its shares.  The Reporting Person and the independent trustee share the power to direct the disposition of the shares. The Reporting Person's adult children are beneficiaries of the trust and thus their pecuniary interest
is attributable to him.</footnote>
    </footnotes>

    <remarks>This amendment is being filed to correct the date of event.</remarks>

    <ownerSignature>
        <signatureName>/s/ Lyman B. Dickerson</signatureName>
        <signatureDate>2004-02-26</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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